Radix

Radix at Three - a retrospective

2012-01-19T21:34:00.000Z

Looking at the calendar, I realise that Radix: The Blog has been going for an astonishing three years. For those of you who have slogged through my prose, I expect it feels longer.

Due to work commitments over the next few months, it will be hard for me to post as often as I'd like, so I'm taking this opportunity to look back (not necessarily in anger) at the highs and lows of root crop exploration. And eat that cupcake.

Highs

Producing some decent crops of oca seeds which I have been able to distribute to others.

Getting said seeds to germinate, grow and produce an interesting range of new oca varieties. I'm still waiting for that elusive day neutral one, but it can only be a matter of time.....

The discovery of oca's ability to sow itself and produce tubers all within one growing season.

Managing to trick my mauka plants into flowering and producing viable seeds; getting the seeds to grow.

Setting up the Radix Root Crops Facebook page - I've learnt a lot from this kindly bunch of alternative root crop obsessives.

Obtaining seeds from the most northerly growing diploid hopniss plants in the USA (read: the world) - which may or may not yield something better than the average hopniss; time will tell.

Growing sweetpotatoes from seeds produced in the Highlands of Papua New Guinea. OK, yields weren't great, but they grew.

Solving the mystery of the hybrid yacons raised from seed collected by Frank van Keirsbilck.

Lows

Losing virtually all my ocas - twice, thanks to illness and unusually cold weather. And my yacons and virtually any other frost tender roots. Nearly dying myself didn't help much to improve my mood either. Unlike George Michael, I wasn't required to give an emotionally charged statement to the thronging press as I left hospital. I was quietly whisked back to Cornwall in a VW Polo.

The crushing disappointment of the underwhelming performance of yampah - previously considered contender for the carrot's crown. No longer.

Mashua - it grows well and yields abundantly here - I just can't overcome my aversion to the taste of it. Damn.

Ulluco - oh so pretty but - oh no - so temperamental.

So, I wonder what the next three years will bring? One thing's for certain: the world of the unabashed rhizophile will continue to throw up challenges and delights, success and failure.

Cornwall's Tiny Little Oca Cook Off 2012

2012-01-14T07:51:00.004Z

Belated Happy New Year.

Due to circumstances beyond my control (serious illness, cold snaps, congenital horticultural ineptitude), we haven't had the chance to eat very many ocas over the last few years. It's clearly high time to right this appalling transgression of the natural order of things. Conservation through consumption - that's my motto.

So when I was feeling rather peckish the other day, my thoughts turned to the recently lifted oca crop; bake off programmes seem to fill the airwaves these days - I thought I'd stage one of my own. Reaching into my characteristically disorganised oca store, I grabbed the nearest and largest tubers available - the ones which the voles, mice, rats and other assorted rodents hadn't yet reduced to fragments. It turned out these were varieties I got from Frank van Keirsbilck over in Belgium, although some of them were raised from seed I sent him.

I gave them a quick wash and popped them into the oven. Before that, I took these farewell pictures, which catch their comely proportions quite well. I suspect that the long, mild autumn gave them plenty of time to bulk up.

Flesh colour varied according to variety, with the large one above being white, despite the colour of its skin; the pale yellow ones were yellow (d'oh) and Frank's excellent variety 'Pink Dragon' (far right) also had yellow flesh, with dark red staining.

None of them were overpoweringly acidic as is sometimes the case with ocas - they all tasted very pleasant. There were differences in texture, with the big stubby one having a slightly more floury texture than the others; the long pale ones were almost buttery in texture. Others more competent than I are exploring the delights of oca cuisine - check out Carl's recipe for warm oca salad.

Although oca was introduced to Europe in the 19th century as a potential replacement for blight prone potatoes, I think it has its own distinctive taste and a bold, attention-grabbing appearance. I reckon it makes very good eating and fits well into contemporary foodways here. If we can just knock a few months off the production cycle, we'll have ourselves an excellent new carbohydrate source and an eye-catching one at that. The Radix quest for a day neutral oca continues; you can be part of it.

Kaukau v Cornwall - the Results

2011-12-13T08:02:00.000Z

At about the same time as I harvested those oca seedlings, I decided to lift the kaukaus, the New Guinea sweetpotatoes, which I grew from seed this year. As per usual, I was a bit late in doing this; sweetpotatoes don't like frost and don't grow at low temperatures - why would they? They're a warm weather plant and express their disapproval of our conditions by producing piffling crops.

Papua New Guinea is located in the tropics, of course, but has extensive areas of sweetpotato cultivation in the cool highland regions. The idea was that plants from high altitude areas might show some increased tolerance to the cool weather we tend to have during the months laughably referred to as summer. Sweetpotato is well known to be a frighteningly heterozygous outcrosser; favourable combinations such as cold tolerance could theoretically pop up each time the random gene generator shuffles the deck and seeds are produced. Over time, the plants best able to cope with cooler weather produce more seeds and this characteristic increases in frequency in their offspring. Yes, folks, I'm taking about evolution.

Being a paid up member of the sow-it-and-see brigade, I decided to put this theory to the test. And what of the results? Mixed - just like the genetics of the seeds themselves.

These are the Teptep roots, three of which showed some thickening; the other two didn't. I quickly consigned those to the compost bin.

The Gwarawon brood all had beautiful red skins, or at least the ones that actually developed thickened roots did, only two in this instance. As previously, I shoved the runners up into the compost.

As these pictures capture the awesomely paltry nature of the yield, I decided to take a few close-ups.

I think the string of sausages effect shown here is due to the cramped pot conditions prior to planting out. That's my excuse.

The white Teptep might make a decent snack. I console myself with the knowledge that it's bigger than the average ulluco.

Some may brand me a simple-minded apologist for the inadequacies of my kaukau plants - but I don't think so. In their defence, I would point out that they withstood some fairly unfavourable conditions - stunted by my neglect, they were planted out late, during a period of drought in which our water supply dried up. This did not exactly aid their establishment. Nor did the unsummery weather during the summer, when long days ought to have joined forces with higher temperatures and plentiful sunshine to get those roots swelling, but didn't. It's remarkable that they did anything at all.

OK, so you think I'm being unduly kind to these feeble specimens? What's clear is that it isn't beyond the wit of humble horticulturists to sow and evaluate sweetpotatoes in the privacy of their own gardens. I managed it, under distinctly suboptimal conditions. Come to think of it, suboptimal conditions are exactly what's needed to locate those exceptional individuals with the ability to shrug off the worst our weather can throw at them.
I may even have another go next year.

If you think you can do better, I hereby throw down the Radix gauntlet and challenge you to breed a better sweetpotato for British conditions - and then share it with me.

A Fistful of Ocas

2011-11-27T18:08:00.000Z

Spurred from my lethargy by the signs of recent vole activity and a couple of mild frosts, I decided to lift two of the volunteer oca seedlings. I had already received indications that there were tubers to harvest, so I wasn't surprised to discover these beauties.

While not exactly fist-filling in their dimensions, they aren't too bad considering their origins as spontaneous eruptions in the regimented realm of the rocoto bed. Who knows - maybe they would have been even bigger without competition from the chillies and the attacks of the voles.

This is the total yield from the two varieties, minus the numerous stolons and baby tubers chomped by the voles before I stepped in. Not too bad for a couple of young ragamuffins from the wrong side of town.

The Cornish Crest shows a fisherman, a tin miner and an oversized chough, which seems to have flapped in from the Lord of the Rings franchise. I'm wondering whether the miner would be willing to stretch out a hand and display what could, potentially, become another local symbol: a shiny oca tuber. It does seem perfectly possible that oca might be established as a successful niche market crop here in the far south west, if shorter season varieties can be bred. I've established (I think) that oca seedlings could theoretically be grown en masse outdoors and selected carefully for relevant traits; I am currently exploring the best ways of ensuring that this happens as soon as possible. I am also proposing, somewhat immodestly, that the count(r)y's name be changed to Ocarnwall as part of a rebranding exercise culminating in a twinning ceremony with Peru.

After soaring whimsically with the choughs, gravity demands that I return forthwith to the ground and face a few facts. My days as oca's wrinkled retainer may be numbered; this Andean adventive is settling in rather well and seems quite capable of pursuing its own independent destiny with precious little input on my part. If the voles let it.

I Think, Therefore I Yam

2011-11-17T07:59:00.002Z

I'm not misquoting the late, great Rene Descartes, natural philosopher and mathematician, whose phrase cogito ergo sum has been spouted ad nauseam by have-a-go intellectuals for years. Nope, that's not what I mean. Neither am I using the word yam as an obscure verb to describe my penchant for eating in a manner famished, nor as an indication that I am spouting nonsense in an animated manner. It is true, however, that I can and will do both of these if circumstances demand it.

What I mean is that all right thinking people, gardeners and natural philosophers ought to investigate the edible potential of the Chinese yam (Dioscorea polystachya). This is a member of the great and still thoroughly extant genus Dioscorea, which inludes many other edible species.

The Chinese yam comes from temperate areas of, you guessed it, China, along with Korea and Japan. It's also found as an introduced (read: highly invasive) plant in the USA and should not be planted in those parts where it is likely to be a problem. It's a dioecious (male and female flowers on separate plants) climber and not unattractive. It's also vigorous, as this picture taken last year at Frank van Keirsbilck's garden shows: estimated height 4 metres. The lack of a suitable pollination partner doesn't bother it one little bit. In lieu of true seeds, the Chinese yam produces large quantities of bulbils, or more correctly, tubercles, in its leaf axils. These drop off and establish new plants, hence its potential as an invasive weed.

My understanding (correct me if I'm wrong) is that the majority of plants under cultivation are male, so true seeds are rarely formed. If and when they do develop, they're probably produced in seed pods that look something like these on D. caucasica, which I took in Ghent last September. As well as being consumed as a root crop, it is also used in Traditional Chinese Medicine for numerous complaints.

Strangely, Chinese yams have attracted the attentions of a philosopher of an altogether different ilk: Rudolf Steiner. Steiner, the founding father of Biodynamics, thought very highly of the Chinese yam, due to its unique ability, in his opinion, to store light ether in its roots. According to Steiner, this made its cultivation in Europe essential to maintain human health. He envisaged it replacing the good old spud as a staple, due to the latter's tendency to make both people and animals materialistic. I think he meant the opposite of spiritual rather than an atavistic compulsion to hang around shopping malls. So what on earth is "light ether"? To me, all this is not only etheric, but esoteric. The fact that Usain Bolt, sprinter extraordinary, is supposed to attribute his speed to the Trelawny yams he grew up eating in Jamaica, just adds to the peculiar allure of this plant. But surely the Trelawny yams aren't D. polystachya, as some reports I've seen suggest, but D. cayensis.

Image courtesy of Dr Markus Heyerhoff

The Germans seem to have taken Steiner at his word and are now growing the Lichtwurzel (light root) on a limited scale, particularly in the Bodensee region. Cultivation practices look somewhat elaborate, involving greenhouses and wooden boxes. Several companies are now marketing the roots and products derived from them.

I contacted Dr Tobias Hartkemeyer at the University of Kassel, located in the raccoon heartland of Germany, where they have been running a research and development project on the Chinese yam: Lichtyams. I was keen to know whether they had been able to breed any new varieties. Tobias told me he had managed to get a female plant, but this had failed to thrive and he has been unable to produce any true seed so far.

The young shoots resemble those of black bryony, (Tamus communis) the only native British climber in the same family, the Dioscoreaceae. This seems to occur in every hedgerow hereabouts and has attractive glossy leaves and in the autumn, on female plants, bright red berries. I really like black bryony, but confusing the roots of the two species is the kind of mistake best avoided. Black bryony's roots, yam-like in appearance though they may be, are powerfully irritant and likely to send the diner on a trip to the local hospital. Luckily, perhaps, the bryony emerges many weeks earlier than the yam and is unlikely to be confused with it. I do wish the yam showed the same early growth as the bryony, though - it might yield much better.

I'm no stranger to the Chinese yam, having grown it several times in the past, but, if I'm honest, I've hardly ever eaten it. This is probably a shame as it really is supposed to have beneficial effects on one's intellectual, cognitive and spiritual development - according to Steiner that is. It's also very tasty, something which tends to have a greater influence on my choice of food than considerations of continuing spiritual evolution. The biggest intellectual stimulus I have had from from growing it has always occurred as I attempt to figure out how to extract the long, thin, brittle roots from the soil without breaking them. As you normally have to wait several years before they reach a harvestable size, they also provide you with ample opportunity to develop reserves of patience.

So with all this in mind, I got myself some yam bulbils - two varieties, species even, described as Dioscorea batatas and Dioscorea japonica. These names are doubtless obsolete synonyms which some obliging taxonomist will delight in pointing out to me in due course. On the left are the somewhat smaller bulbils of D. batatas, on the right those of D. japonica.

I'm not much of a party animal, but it's often possible to pick up a few plastic cups at such events; these make serviceable pots for long rooted plants, at least in the early stages of development. Judging by the appearance of what might be politely described as finger-like protuberances from the bottoms of these cups, potting on is now required. My finger is on the right, in case you're confused. The only discernible difference I can see between the two types (species?) is the greater vigour and precocious bulbil development on the D. japonica plants.

Some American polyculture enthusiasts have abandoned the shovel and are now harvesting the yam bulbils as the main food instead. The 'yamberries' as they are calling them, seem to yield very well in their climate in New England giving 3-4 US gallons per plant (I think that's around 12-15 litres) in Holyoke MA. They're certainly miniscule compared to the the fist size ones produced by the air potato, D. bulbifera, but they seem to make up for this by being produced in large quantities. Lightly toasted on a skillet, or in the oven, they are apparently very good eating. A root crop that doesn't require digging - is there no end to the diverse talents of Dioscorea polystachya?

This is an intriguing plant, with delicious roots and all sorts of associated mystique, half-truths and misinformation. Aside from the necessity of mining the roots rather than harvesting them, the main problem, in our climate at least, is their late emergence in the spring and subsequent slow maturity. If plants of different sexes can be located, it might be possible to set up a Dioscorea dating agency and breed varieties that are better adapted to our climate. There are, apparently, numerous sorts found in China, with varying shape, size and number of roots. So, to any Chinese yam enthusiasts who have male and female plants in their possession, Radix awaits your call.

A Profusion of Pods

2011-11-07T08:01:00.006Z

The mild weather over the past few weeks has led to a bumper crop of oca pods. There are many hundreds, if not thousands of them adorning my plants at the moment. It may be a bit optimistic to harvest them all before frost strikes, but I'm going to give it my best shot. There's no way that bagging them individually can be achieved, so I'm just gathering those that are close to ripening and storing them as described previously; it seems to work. I'm not the only one experiencing success either - Ian at Growing Oca reports similar success, as does David Taylor, who has been contributing to a discussion about oca seed production on the Radix Facebook Page.

Here's an oca tuber from one of last year's seedlings, looking plump and well developed.

The flip side - literally - tells another story: vole damage. Not content with eating fully formed ones, they also enjoy severing the stolons to which the developing tubers are attached. In addition to this outrage, they've conducted some impressive pumpkin carving on our squashes, many of which are scarred by hundreds of tiny incisor marks. Ah, the joys of wildlife gardening.

While I was collecting the pods from the volunteer seedlings, I couldn't resist tunneling beneath the surface, just like the voles. And this is what I found - a quite impressive cluster of tubers, all things considered. So it's possible for oca seedlings to appear spontaneously, flower, produce seeds and tuberise - all within one growing season. I think this is what they call progress.

Who Tampered With My Yampah?

2011-11-01T08:30:00.003Z

I have a guilty secret. You're looking at it, or rather, them. Magnifying glasses at the ready - these are my yampah roots. I've been debating for several months as to whether I should reveal them in all their maddeningly minute glory. That time has now arrived.

Although yampah roots are spoken of very highly as a wild food, this rate of growth really doesn't bode well for their general productivity as a garden crop. Let's just say the potato can lie in its bed a little longer without fear of being usurped.

As so often follows failure, a period of doubt and self-recrimination ensued. Was it the compost, the temperature, transplanting shock? Insect damage perhaps? Something or someone was to blame. Maybe I'm an even less competent horticulturist than I ever realised. I have had them stashed in some vermiculite, hidden from view, while pondering on all of this.

Then last night, I was idly perusing a document from the USDA Forest Service on a related yampah species, Perideridia erythrorhiza, when I came across this quote:

Work in the greenhouse indicates that juveniles will senesce 8-12 weeks after emerging, even if kept well watered, and will not flower the first year. During this early period of growth, a single small tuber 1cm or less is developed, which then remains dormant until the following spring.

That's it. That's exactly what happened.

So roast yampah roots won't be on the table this Christmas, but I might get another stab at growing this queen of North American wild foods. And it's really not my fault.

Mauka Makes My Day

2011-10-23T19:18:00.000+01:00

I don't know what's up with my biorhythms at the moment, but I seem to be rather accident prone. I managed to poke myself in the eye with a branch a while ago. It hurt like hell and I had a brightly bloodshot eye for several weeks. More recently, I burnt my hand while getting something out of the oven. And as a result of carelessly deseeding chillies yesterday, my fingers are now a lethal weapon whenever they come into contact with delicate areas of my anatomy. And to think only a couple of days ago, I was innocently listening to "Ring of Fire" by Johnny Cash, without the least intimation of what was to follow. True.

So I'm feeling in need of a little cheering up. Mauka, bless it, has provided me with a welcome late October fillip. Here it is, a mauka anthocarp, freshly harvested from the Blanca variety.

The plant itself looks to be undergoing a bad hair day of its own - it's a mass of straggling shoots with drooping (and dropping) yellow leaves; ornamental it is not - more like an oversize urchin gypsophila than anything else. But it is flowering gamely despite all this and even though I've abandoned my pollination attempts this year, it seems to be setting a crop of seeds nonetheless. I brought it indoors onto the same windowsill where my winged beans once stood, fearing frost would clobber it before its moment of glory. We've had some very mild frosts, but the other varieties, which I have left outside to their fate so far, are also flowering now; they show signs of swellings where swellings should be, from which I deduce that fertilisation has occurred. Mauka, I think I love you.

From Seed to Seed - Oh Yes, Indeed

2011-10-18T17:24:00.002+01:00

This frankly unremarkable picture of some frankly ordinary oca seeds hides a portentous event. For me, that is. These are the seeds I've just collected from the self-sown oca seedlings that sprang up unannounced and, if truth be told, inconveniently among the rocotos. It is, therefore, theoretically possible to produce an annual supply of oca seeds outdoors in our indifferent summer weather, without recourse to any elaborate horticultural facilities. Reaping what you sow, all within a single season - that's surely progress. I am preparing myself for the inevitable media onslaught that will ensue from this paradigm-shifting, epochal moment in the ongoing acclimatisation of oca. Don't all rush - let me comb my hair and clean my fingernails first.

Gotalottacacomitl

2011-10-10T09:02:00.001+01:00

I've just been collecting Tigridia seeds from the bulbs I planted back in the spring. It's been a bit wild and wet lately, which is probably not conducive to cacomitl seed health, so I've decided to delay no longer. Although cacomitl seeds can and do germinate successfully as volunteers in this part of the world, I find it hard to believe that sitting in a soggy pod for weeks on end will do them much good.

Now if I had the time and space (both physical and mental), it would be fun to sow the whole lot and then select the plants for the biggest bulbs, just like Luther Burbank did. The best bulbs would be allowed to cross-pollinate and the rest would be eaten. This would be a highly satisfactory way of incentivising plant breeding in my opinion. Cacomitl's easy and amenable nature and obvious fecundity might, with sufficient selection effort, yield up something worthwhile. With their excellent flavour, it is only the small size of the bulbs that keeps them typecast in the role of amusing ethnobotanical footnote.

Ironically, I suspect that removing the immature seed pods might have a much more immediate and positive effect on bulb size than years of painstaking selection. If the behaviour of other plants is anything to go by, this would divert energy away from seed production and into vegetative growth; you can't win 'em all.

The Windowful Winged Bean

2011-10-03T09:16:00.002+01:00

Psophocarpus tetragonolobus - not just a name to conjure with, but a useful tropical crop that's commonly known in English as the winged bean. The pods have extravagant flanges from which its name derives and pods, seeds, flowers, leaves and swollen roots are all edible. They say every bit of a hog can be used, from its tail to its squeal - the same is apparently true of the winged bean. If you're interested in its potential, you can read all about it here in a venerable document from the 1970s. Suffice to say, winged bean has generated considerable enthusiasm among researchers and is a member of that elite corps, nitrogen fixing root crops.

Winged bean loves heat and humidity. I've tried to grow it outside here on several occasions, but to no avail. Cornwall is certainly humid, but, although it's said to be the warmest part of the country, this is a partial truth worthy of estate agents and tourist boards. Warmest in winter is more accurate. Even that's not strictly true - it's just less cold than most other parts of the UK. As a corollary, our summers are generally cooler than other areas of southern Britain, due to the moderating influence of the sea.

So growing winged bean outdoors in the UK seems to be an exercise in futility. My guess is that if you have the kind of summers where you can lounge around in a Hawaiian shirt all night and not get in the least bit chilly, you can grow winged bean in your garden. But, even if you are able to provide it with the right climate, most varieties are daylength sensitive and refuse to flower at a sensible time of year when grown away from the tropics. But not all: meet Hi-Flyer, a variety bred by the USDA that has the potential to flower in our long, often-not-so-hot summer days.

I've been fooling around with Hi-Flyer on an occasional basis for more than a decade. I think I last grew it back in about 2003 in an attempt to regenerate my seed stocks. And I was successful in this endeavour - my single plant grew, flowered and formed a couple of pods, all on a not particularly sunny windowsill, in a not particularly warm house. The sky blue flowers were attractive - big and bold and yet somehow rather delicate; I wish I'd taken a picture of them. The pods were a sight to behold too; once again I regret failing to capture their architectural quality.

This year, I thought I'd kill two birds with one stone: replenish my supply of seeds and finally get around to eating the roots. In Papua New Guinea, the winged bean is particularly popular and is known by the Tok Pisin name of "asbin". Asbin roots are considered a delicacy and special sing-sings (festivals) are organised to celebrate the harvest. I wasn't exactly envisaging a lavish shindig: there was only enough space on the windowsill for two small plants. Opinions on the flavour and desirability of the roots vary, but seem to coalesce around "nutty" "beany" and "earthy".

I sowed seeds in about March and plants finally emerged; I potted them on and left them on the windowsill. For a while they grew well, then suddenly they stopped growing and all blandishments in the way of repotting, feeding and watering were as nothing. Not a single flower bud appeared on either plant. Scratching around in the compost, however, it was clear that there were some thickened roots. It's well known that other leguminous tuber crops do better when their flowers and pods are removed; perhaps this is the case for winged bean and I had inadvertently created the right growing conditions for tuber formation. I'm utterly mystified as to why they refused to flower, especially as this has never been a problem in previous seasons.

So, for some unknown reason, Hi-Flyer barely got off the ground and could be said to have nosedived, at least in the case of sexual reproduction.

I'm now debating whether I should spare both roots, plant them next season and delay gratification until fresh seed stocks have been produced, or just plough on regardless, eat the roots and repent at leisure if my remaining seeds prove unviable - Radix's reworking of the Goose That Laid the Golden Egg. Let me know your thoughts: the fate of these two plants lies in your hands. In any case, I reckon Hi-Flyer winged bean might be worth growing in a greenhouse or conservatory as an all-purpose edible plant for those closet permies out there; you know who you are.

Mauka: Man Bites Dog (Again)

2011-09-29T09:00:00.001+01:00

Yawn. Once bitten, twice bored. The shove-'em-in-a-shed™ technique of inducing flowering in mauka that I first used last year has worked again. Same 11 hour day, for about a month - same result. Frank van Keirsbilck has been trying his own version of this technique and he tells me that his plants are also in bud.

The first up is Blanca, with flowers opening now. Both 208001 and Roja are snapping at Blanca's heels, with the beginnings of inflorescences easily discernible at the ends of their stems. I hurried out specially in my pyjamas, before the sun was up, to get this shot of Blanca in all its understated glory. As I mentioned before, the flowers seem to open, not in the afternoon as might have been expected from the behaviour of other members of the genus Mirabilis, but at night. Four o'clock flower indeed.

Although this is far too late in the autumn to reasonably expect the flowers to be pollinated and produce a viable crop of anthocarps outdoors, it at least shows that mauka is amenable to this sort of unsophisticated daylength manipulation. All you need is a shed, a mauka plant and a fairly accurate timepiece. Interested?

Mauka: Expansa by Name, Expansive by Nature

2011-09-25T20:09:00.000+01:00

As the nights draw in, it feels like the right time to be taking stock of the various successes and failures at Oca Acres.

Let's start with a success story. This is me modelling a young mauka seedling a few months ago. For some unaccountable reason, I seem to have clean fingernails - apologies for the oversight.

These same mauka seedlings have matured into vast, hydra-like monsters, bulldozing all in their path. Usually mashua (Tropaeolum tuberosum) can hardly be described as a good neighbour, what with its unabashed delight in strangling its bedfellows. This year, though, things are different and I feel an unfamiliar wave of sympathy for it; the poor thing has been utterly trounced by the march of the maukas. This was the state of play back in the early summer - that's the mashua at the bottom left.

That was then; this is now:
The vertical object at the back is a shovel, a long handled one; the plants are now about a metre or so high and considerably more than that in total length. They're refreshingly vigorous. Of the mashua, nothing can be seen.

The weather for the last few months has been disappointing - nothing new there: lower than average temperatures and lower than average sunshine. Apparently it's been the coolest summer for eighteen years.

The maukas, however, seem to have been wholly unconcerned by any aspect of these temperature and insolation anomalies. About the only things to check their growth were a few aphid infestations on a couple of shoots, but even those seem to have passed. Given reasonable levels of care at the beginning of the season, mauka does seem to be a toughie and, let's not forget, actually tastes rather good. It should also be remembered that it is a rare crop even in the Andes, where the total area under cultivation is reported to be around 10 hectares. Scary. To the best of my knowledge, this patch is probably the biggest one between here and Belgium, where Frank van Keirsbilck grows quite a bit of it.

Frank has produced roots weighing more than 2kg from a single plant. Mine have never been quite so large, but my main interest is in trying to duplicate those descriptions of earthed-up stems thicker than a man's forearm, which feature in Lost Crops of the Incas. The best I've managed so far are these from a couple of years ago. There is still much to learn about this plant and how to cultivate it, but I do like its attitude. Rare it may be, but it's also raring to go. Up and at 'em, Mauka!

Will the Cycle Be Unbroken?

2011-09-17T08:11:00.000+01:00

I sincerely hope so, because these are my very first self-set oca pods to appear on the self-sown oca seedlings that I mentioned previously. I've been away for a while and now I'm back; seems like it's a case of absence makes the pods grow longer. With a bit of luck these may yet ripen, thereby demonstrating that the whole oca life cycle can be completed, seed to seed, outdoors, in the Cornish climate. I know it's not over until the fat pod pops, but I'm really quite excited by the prospect of this latest development.

Gotcha!

2011-08-18T08:49:00.000+01:00

I've just harvested my first few oca seeds. That's why I'm all smiles.

The pods from which these seeds were collected lay hidden in the lush foliage the plants have been producing recently. I noticed them while I was bagging up some other pods. As I've mentioned before, oca pods are small, unremarkable in appearance and restrained in colour. It's easy to overlook them. That said, they do pack a Lilliputian punch - on several occasions I've been pelted with miniscule buck shot as a pod explodes close to my face. It doesn't hurt, but can cause a momentary loss of concentration - not what you need when you're trying to retain your balance and insert some awkwardly aligned pods into a tiny little envelope.

Unripe pods tend to hang pendulously; as they approach maturity they raise their heads and finally disgorge their cargo courtesy of slingshot arils that catapult the seeds up and out. Even if your oca plants aren't setting any pods, you can witness a similar effect with the common weed Oxalis corniculata. It uses the self same explosive dispersal mechanism. What this means of course, is that seed harvest is a fiddly, not to say tedious, process, punctuated by moments of high drama and relies on due diligence on the part of the gardener; with oca pods, timing is everything. I think of it as a cross between plant breeding and bomb disposal. Anyway, I grabbed the pods from which these seeds were about to escape and stuffed them into an envelope; within a few minutes they were out.

And here's something you don't see very often: a volunteer oca seedling flowering amongst those rocoto chillies I mentioned in my last post. With a bit of luck (and some obliging bumble bees) it should be possible to get some of these to complete the oca lifecycle, seed to seed, with zero effort on my part. Now that's the kind of plant breeding that really appeals to me.

Budzaburstin

2011-08-01T07:27:00.000+01:00

Flower buds, I mean - oca flower buds.

The unsummery weather we've had until fairly recently, with heavy rain and strong winds, doesn't seem to have fazed the ocas at all. They're keen to give their all in the Reproduction Sweepstake. I'll just have to follow on behind as per usual, with little envelopes to collect the output of the random oca generator.

Flowers have been appearing sporadically for a couple of weeks, but it looks like the high season is now upon us. I can see plenty of my 100+ plants with plenty of flowers. Let the riotous season of cross pollination commence.

One concern I have is the relative scarcity of bumble bees so far this season. I'm pretty sure that Oca Acres was fairly ringing to their buzzing last year. This year is different: hardly any were to be seen until the last couple of weeks. I don't think I even glimpsed a single honeybee until a few days ago, which is highly unusual. Apart from my obvious worries about the decline of well-loved insects, I don't really want to go back to the dark (daft?) days of hand pollination if I can avoid it. The bees and hoverflies seemed to do a much better job than me without the general tetchiness and backache I experienced when transferring pollen.

I notice that one of my self-sown seedlings is now in flower. This isn't Prima, but the second plant to appear, henceforth to be known as Compay Segundo. If this and other similar seedlings flower and set seed, the whole oca lifecycle will have been achieved alfresco - another step in the long road to acclimatising the plant to our conditions.

And here's a sight you don't see very often: volunteer seedling ocas appearing as the understory amongst some rocoto chillies (Capsicum pubescens). If this sort of polyculture cropping appeals to you, head to the Growing Oca blog, where Ian seems to have perfected the art of oca associations in the vegetable bed. In the meantime, I'll keep plugging away at finding a day- neutral, heavy yielding, tasty and ravishingly beautiful oca. Wish me luck and never mind that it's started raining again.

Bulbous Belly Border Blooms - Beautiful

2011-07-16T07:59:00.000+01:00

Alliteration may be the lowest form of literary wit, but why break the habit of a lifetime?

Those cacomitl bulbs, purchased from the bargain basement of a cut-price supermarket, are now producing some impressively large and colourful flowers. Like Hemerocallis, each flower lasts only a day, or quite a bit less in the case of Tigridia; by late afternoon they're already pretty much closed. Most of the time I only get to see the withered remains, but I caught these ones at about 3.30pm, just before they started to deflate.

They're growing on top of rather stunted plants, about a foot and half tall, with interestingly pleated leaves. So far they've survived drought and the unwanted attentions of the local voles who took to gnawing through the emerging shoots. As far as I'm aware, they didn't tackle the bulbs. This may be due to the unpleasant burning sensation they cause if you eat them raw.

Pretty as the flowers are, we all know that they're merely a vehicle for plant sex. I took the opportunity to have a look at their reproductive structures more closely. I can confirm that pollen is produced in large quantities and attaches easily to the sticky stigmas. I couldn't resist giving them the Luther Burbank treatment - I cross-pollinated the flowers; this was altogether unnecessary - I saw several seed pods in various stages of formation - but fun nevertheless. It should be easy to collect the seeds as they ripen. Even if I fail in this bid (I often do), it should not matter - they're known to self seed quite successfully in our climate. I did once have some seeds from wild Mexican plants; it would have been good to compare these cultivated bulbs with those, but I must have lost them sometime in the last fifteen years. Still, if anyone would care to provide me with replacements, I'm sure I could do a better job next time around. Por favor.

What Now, Kaukau?

2011-07-11T20:00:00.000+01:00

If the Ipomoeophiles among you have been wondering what became of those Papua New Guinea sweetpotato seedlings, these pictures should provide an answer.

They've grown and turned into a bunch of small sweetpotato plants, just as I'd hoped. It's interesting to see the diversity of form they show in leaf shape, leaf colour, habit and vigour. Sweetpotato is a hexaploid, highly heterozygous, obligate outcrosser, so seed raised plants are likely to show all sorts of random combinations of characters. What I'm hoping is that these ones, from stock high up in the mountains, will show increased hardiness in our climate. No guarantees of course, but one can but try. To help me in my selection process, I might well turn to the Sweetpotato Knowledge Portal to show me where I've been going wrong.

So the next step (late though it is) is to stick them in the ground and see how they cope with the Cornish summer; not for the first time, this seems to consist of alternating rain, gales and brief salvoes of scorching sunshine.

What now, kaukau? The answer's easy - I'll plant you out, tout de suite. But planting space at Oca Acres is running a bit low at present. Where now, kaukau: that's the real question.

Hot Date at Dartington

2011-07-07T19:30:00.001+01:00

The question was: what to do with a scruffy collection of surplus-to-requirements Andean root and tuber crops? The answer, obviously, was to set up an Andean polyculture bed at Dartington - Schumacher College, to be precise.

As I have been known to pontificate incessantly about the value of conservation through dissemination, it is wholly appropriate that I should now act on my beliefs. I proposed the idea to Bethan Stagg, Lecturer in Ecological Horticulture at the college and she seemed to like it.

So it was that I rocked up at the college with some tatty looking oca, mashua, yacon and mauka plants and we wandered off to a patch of ground next to one of the college's buildings.

The plot chosen by Bethan was a sunny, otherwise unoccupied bed; just across the path, within easy lobbing distance of a blighted potato, was the Agroforestry Research Trust's iconic forest garden. Ideal.

My comrade in the planting was Dave Hamilton, author, blogger and horticultural tutor at Schumacher College. I'd never met Dave before, so what better way to break the ice than to discuss the design of our Andean tuber polyculture and then rehome these horticultural waifs.

The theory is this: the yacon will form a tall framework at the back, which the mashua, courtesy of its prehensile petioles and scandent habit, will scramble up with aplomb. The oca and mauka, with their spreading, sprawling growth, will elbow out or smother any impertinent weeds that challenge them. I make no claims, expressed or implied about the authenticity of this combination - it just seemed to make the most sense to me. The problem is the timing: it's late and the plants are shamefully small, no - let's be honest here - stunted. It's not impossible, however, that summer will return and their roots will reach into the deep, rain-recharged soils. If those conditions are met, I see no reason why they shouldn't romp away. That and a long mild autumn and perhaps all will not be lost.

If this year's experiment proves successful, perhaps it might be possible to try something similar, bigger, involving the students. Bethan has hinted that this is not an entirely ludicrous idea.

Following a delicious Schumacher lunch (thanks Bethan!), I bade my farewells and headed back for Cornwall, the homeland of Radix.

I may not be able to get over to Devon and check on progress as often as I would like, but think only this of it: That there's some corner of a foreign field. That is forever Radix. (Sorry, Rupert Brooke, but I couldn't resist it).

Oca: Solace at the Solstice

2011-06-23T19:30:00.051+01:00

Flaming June? No, not exactly - more dripping, when it isn't blowing a gale, that is. We prayed for rain for two long months and now we've got it; my mother was always telling me to be careful what I wished for. While the stunted vegetables that gasped in the dry spell are now mostly plump and perky, the slugs that feed on them are also looking pretty sleek.

Many of last year's oca seedlings were annihilated when the winter's early cold snap caught me out. The majority of my original varieties copped it as well - not good. All is not lost, however: thanks to the generosity of Frank van Keirsbilck and Graham aka MyBigHair, I have managed to source most of the missing varieties as well as get some new ones which they raised themselves - I get by with a little help from my friends.

I've only been able to produce a paltry thirty oca seedlings myself this year; you could say I've been feeling a little underwhelmed by my success. But now the gentle rains of summer (huh) have caused an impressive flush of oca seedlings to appear - I've discovered around twenty popping up spontaneously in various beds. This means I must now be close to having the 100+ varieties I had last year - a cause for minor celebration in the Radix household. We may have failed to see the sun setting on the longest day - the lowering black clouds saw to that - but things seem to be looking up.

Have Hopniss, Am Happy

2011-06-06T11:30:00.006+01:00

Seeing as I am already in possession of several hopniss varieties, I ought to rephrase that: more hopniss makes me happier. I'm talking about the pleasure I'm experiencing from sowing the seeds of northern adapted plants and savouring the resultant increase in the genetic diversity of my hopniss collection. Aside from anything else, it's always exciting when seemingly inanimate seeds burst into life. These diminutive seedlings seem to be vigorous and healthy. In fact, they're actually a little too vigorous and are now spiralling (always anti-clockwise) out of control. Untangling this lot could prove an intellectual challenge and it ought to sharpen my hand-eye coordination as well.

It's not the first time I've grown hopniss from seeds. Back in the early 1990s, I obtained a batch from Bill Blackmon at the Louisiana State University in Baton Rouge. They had themselves a serious breeding project, which was going great guns and was all set to catapult this plant into the mainstream when, horror of horrors, funding was withdrawn; Apios slithered back into the swamps of Louisiana and beneath the waters of oblivion.

To be honest, the Louisiana seedlings grew very poorly for me. This is hardly surprising considering their provenance: more Clifton Chenier and crawdads than clotted cream and pasties. But the lure of a nitrogen fixing root crop proved too much and well, here I am again, sowing hopniss seeds and hoping for a different outcome. Madness - perhaps, but fun - certainly.

Unlike the LSU seeds, these are from plants in various parts of New England and therefore might be more suited to our climate. In fact, the "Deerfield River" accession was collected at what is currently the world's most northerly known location of wild diploid plants; this is a clean fifty miles further north of any other sites, near Charlemont MA and not far from the Vermont border. Thanks are due, once again, to Bryan Connolly, who very generously keeps me supplied with seeds and site information. Triploid plants occur right up into Canada, but these are sterile, so present Radix with some problems when it comes to a breeding programme. They are, however, hardy and particularly vigorous, as polyploid plants often are.

As to these diploid seedlings, I have no idea as to whether their northerly origins will equip them any better for the rigours of our climate, but it might just make breeding better varieties a possibility. There's only one way to find out - so come on now hopniss and let the bon temps rouler.

Mauka: The Next Generation

2011-05-30T12:00:00.001+01:00

Here's a quick update on the mauka seedlings which hatched just over a month ago. Their growth has been rapid to say the least and they are in need of hardening off and planting out.

You may not be able to see it, but the 'Roja' seedlings are developing red stems, whereas the 'Blanca' ones are green - they apparently cleave unto themselves as regards stem colour, although I've no idea about any other, more subtle characteristics. What I do know for sure is this: simple daylength manipulation is enough to get the plants to flower and set seed. The fact that the seeds show excellent viability and produce vigorous seedlings leads me to stick my neck out and say that breeding mauka is going to be one of the easier gigs for Radix.

Given mauka's ability to thrive in windy, dry areas, this is probably a good thing - we've had virtually no rain for months and a strong, cold wind has been an almost constant irritation. I could moan, but what's the point? Taking my lead from luminaries such as Sigmund Freud, Billy Connolly and Alfred Wainwright, I lay out my philosophy thus: there's no such thing as bad weather, just inappropriate root crops.

Don't Tamper With My Yampah

2011-05-25T09:30:00.010+01:00

I mean that most sincerely, folks, I really do. So, what gives - why the earnest plea? Well, this is the first time I've ever managed to get yampah seeds to germinate, despite several attempts over the years; they're precious and I want them to stay alive. You may already know that yampah (Perideridia gairdneri) is a North American umbellifer. It was very highly regarded as a food in the Pacific North West region by native peoples where it, or closely allied species, occur. It was also traded over a wide area.

Image courtesy of Russel Barsh, Kwiaht

The best bit of the yampah plant is its swollen root, a bit like a mini carrot, which is edible both raw and cooked; not only is it edible - it's sweet and tasty and is reckoned by some to be the nicest wild root in the region, lacking the bitter, off flavours sometimes found in other plants. The seeds are edible too and have an aromatic flavour that has been likened to caraway. Remembering the tale of the goose that laid the golden egg, I decided not to test this, reckoning I'd have my work cut out getting any to germinate at all. One intriguing feature is that the roots are multistelic, that is they produce both a main storage root (the carroty bit) and also lateral storage roots arising from it, an unusual feature for an umbellifer. You can see that in this picture, which is not, I hasten to add, one of my own yampah roots.

My seeds come from Lopez Island off the coast of Washington State, which might just be the closest thing to the Cornish climate that I'm likely to find in the USA. They were generously harvested by Madrona Murphy, a botanist who works for an excellent organisation called Kwiaht which is studying the ecology of the Salish Sea. Aside from persuading her to collect seeds for me, we have had fascinating discussions about the remarkably sophisticated agricultural practices of the First Nations of this area, involving camas meadows (of course), silverweed (natch) and surprisingly, woolly dogs bred for their fleeces in the days before European settlement. Who knew? Not me.

Another surprise - the Lopez Island yampah seeds germinated vigorously after a few months in the fridge. I've potted them up, passed a few on to various people and now I'm waiting. I have to say, that after their promising start, the seedlings don't exactly exude brassy confidence at the moment. They have very thin, almost grassy cotyledons and sparse foliage. Wild plants usually occur in grassland, so this mimicry may offer them a bit of camouflage from grazing animals. My plants, by contrast, look naked and unprotected. They seem to be sitting and marking time, which is why I'm eager that they be protected from the attacks of slugs, birds, voles and any other as-yet unidentified threats to their continued existence. Tampering by that crowd will not be tolerated.

I'm getting a little bit suspicious that I may be the author of their stasis: it's possible that their restricted root run in the modules has prevented the development of their tap roots. Could it be that I've inadvertently tampered with my own yampah and created the world's first Perideridia gairdneri bonsai? Better pot them on in that case.

One of the problems I can forsee with yampah is common to other relatively slow growing, single harvest root crops: the time and effort spent in growing these things is just not comensurate with the pay back in terms of delicious food. The descriptions I have read do not suggest that yampah roots are large - about the size of an unshelled peanut is one estimate. I'm not sure that I'm patient enough to wait several years before sampling them.

But that's for wild plants; in cultivation it may be possible to boost yields considerably. Steve Dupey, a tireless and meticulous explorer of plant potential, tells me that providing the plants with decent soil can greatly improve their productivity and treble their size. He also believes that maturity, which usually takes several years, can be speeded up by growing the plants in a greenhouse for a while. Finally, he suggests slicing off the top of the mature root and replanting it, while diverting the rest to the nearest saucepan. With their multistelic proclivities, the tops regrow and you have yourself a yearly harvest of yampah. That's the theory. My seedlings look like they've got a way to go before that could be accomplished without handlens, forceps and scalpel, but I'm happy to eat my words (and the yampah roots) if they put on a sudden spurt of growth in the next few months. Or years.

I Spy With My Little Eye

2011-05-09T09:25:00.003+01:00

Something beginning with O.

Yes, the first oca seedling of 2011 has appeared, not entirely unexpectedly, in last year's oca bed. No squirreling away of seeds in little envelopes, no meticulous bagging of developing pods, just a healthy little plant reporting for duty. Makes me wonder whether I should just let the little darlings get on with it, which is probably the method adopted by the Andean farmers who have developed this crop over several thousand years.

Call me pretentious, but I've decided to name it Prima, the first oca of the 2011 season.

Prima's germination and growth may have been accelerated by the unusually warm April we've just experienced. Looking back at last year's spontaneous oca eruption, I notice that it began somewhat later, in June.

It's fairly easy to distinguish Prima from last year's tubers which are also emerging all over the place: it has a lovely pair of cotyledons - small, but perfectly formed. Just like Adam and Eve's lack of navels, no shoot from a tuber produces these tell-tale appendages. And when I say small, I do mean small - take a look at the adjacent dandelion pappus for an idea of scale. Diminutive stature notwithstanding, I am quietly confident that Prima will be joined by several siblings before the month is out.

Much more obvious than any oca seedlings and frankly, rather disturbing, are the hordes of talet volunteers springing up like leguminous bindweed. The pencil at the bottom of the picture gives some idea of their size. Will no one rid me of these turbulent talets? I'm going to have to evict them; unless someone wants to intercede on their behalf, I'll simply have to hoe them off. A shame, but it does demonstrate that this plant is a survivor and a tasty one at that.

How Now, Kaukau?

2011-05-05T08:30:00.007+01:00

Kaukau, in case you didn't know, is the Tok Pisin word for sweetpotato, pronounced "Cow Cow". Yes, please give a warm welcome to my my first Papua New Guinea kaukau seedlings.

Not being a kaukau expert, I'm not really qualified to say how well they're doing, nor whether they'll prove any more successful than any other sweetpotatoes in our climate. What I do know is that they germinated easily and look vigorous. The seeds came from fairly high altitudes in the Finisterre Range in Raikos, Madang Province. The weather there is, apparently, hot during the day, but cool to cold at night and often misty. Teptep and Gwarawon are two of the possible locations from which they were collected, but I don't actually know for sure.

New Guinea is a fascinating place, with a wide range of climates, from tropical to alpine. The sweet potato is not a native there, but was introduced, rumour has it, about 300 years ago and is now the predominant staple food for millions of people. Estimates of the number of varieties run into the thousands, with wide differences in flesh and skin colour. With that amount of biodiversity knocking around, it's quite possible that varieties with superior cold tolerance may have popped up as well.

I don't have the time or space for this at the moment, but I really think the traditional mound method of growing kauakau might catch on. It's quite similar to the "hugelkultur" type beds currently being promoted by Sepp Holzer, an Austrian farmer and permaculturist. Perhaps by aligning the mound's slope correctly, a hot sun trap could be created for the sweetpotatoes, allowing me to extend its cultivation into the bleak and inhospitable foothills of Bodmin Moor. Other geographically challenged people could do likewise. But for now, I'll just limit myself to savouring these fruits of Papua New Guinea's agrobiodiversity first hand: kaukau, gutpela long bungim yu!

Mauka: Unto Us A Child Is Born

2011-04-27T08:57:00.008+01:00

Last year I managed to hoodwink my mauka plants into flowering. Those flowers produced a seed crop, albeit small, from two mauka varieties, Blanca and Roja. I sowed the seeds about a week or so ago - cue some stirring music from Capellmeister Handel - and here's the result:

Not so much child, singular, as children, plural. Yes, this is a miraculous multiple birth at a much more sensible time of year than December - for plants anyway. They may look like small, undistinguished, generic seedlings to you, but to me they're altogether more wondrous. Hallelujah!

This is, I suppose, the culmination of about twenty years' acquaintance with an intriguing plant. I first became aware of mauka's existence when I got my grubby mitts on a copy of Lost Crops of The Incas in about 1990. I still remember how I stayed up all night to read it. A root crop in the same family as Bougainvillea was a new one on me at that time and the fact that mauka was unknown to science prior to 1965 just added to its mystique. Thus began my protracted efforts to obtain a plant.

Eventually, more than fifteen years later, I realised that ambition. And now I've finally grown my own plants from my own seed: good things come to those who wait.

They Rose From the Dead

2011-04-18T08:34:00.001+01:00

Easter is supposed to be about suffering and death, followed by resurrection and redemption. I try to remember that every time I tuck into an Easter egg. But it's surely no coincidence that Jesus chose a garden in which to reappear after the crucifixion. Gardeners are well placed to experience the cycle of death and life on a regular basis.

Well, I'm glad to report that the losses and sorrows of last winter have been followed by an unexpected rebirth at Oca Acres.

I'm talking about the yacons, or rather the hybrid brood produced when a bed-hopping bit of rough from Costa Rica (Smallanthus riparius?) got together with true yacon (Smallanthus sonchifolius) in Frank van Keirsbilck's garden. I sowed the seeds of this union and some impressively vigorous plants resulted.

A few days ago, I was staring at the bleached and lifeless stumps of last summer's luxuriance and decided that it was time to clear the bed - out with the old and in with the new. Grasping the remains of the nearest plant, I levered the holy relic from the ground, ready to consign it to a nearby pile of combustible material. Blow me if it wasn't sprouting. Several of the other inauspiciously splintered twigs showed similar signs of life.

The storage roots, although very small, do show a little bit of thickening and the new shoots are issuing from something that looks quite similar to your typical yacon propagule. So maybe I've been granted another chance at backcrossing them with some of the true yacon varieties. One thing is sure: they're considerably hardier than my true yacons - all of which were killed in situ by the particularly penetrating frosts of last December. That extra bit of vigour and cold tolerance would be well worth transferring into the yacon genome. So when the flowers appear in the late summer, I'll be there, paintbrush in hand, ready to assist in the process.

From Tiny Talets Towering Titans Grow

2011-04-13T09:00:00.003+01:00

The two new varieties of talet (Amphicarpaea bracteata) are progressing well. I scarified and sowed the aerial seeds a few short weeks ago and now they're up and ready to give life their best shot. I'd better not let them down. I'd better pot them on promptly and make sure that their watering needs are met. You'll notice that the first pair of leaves have a simple, rounded shape, unlike the more characteristic trifoliate leaves which are just starting to appear. These aren't the cotyledons, though, because germination in talet is hypogeal: the cotyledons stay underground, like runner beans.

As for towering titans, I have to admit that I'm not as interested in their final height so much as the date at which they begin flowering and the yield of those delicious subterranean beans. Never a hostage to delayed gratification, I want them big and I want them now.

A Lucky Legacy

2011-04-04T09:00:00.017+01:00

Last year I brought you the tale of Lucky, my very first self-sown oca seedling, which (I almost said who) survived deradication at my hands during a moment's lapse in concentration with a sharp bladed implement. I managed to persuade the top to develop a new root system and I potted up the small plant as it developed slowly over the summer. Lucky lived on until the winter when both of us were caught out by the cold snap. Lucky's pot did what any pot would do under the circumstances: it froze solid. It seemed like Lucky's luck had finally run out.

Lucky's demise reminded me of The Rare Breed, a film about a Hereford bull, Vindicator, who (I almost said which) is transported to Texas to improve the local longhorn cattle. Vindicator perishes in the harsh winter and there are tears all round when his frozen body is discovered. Then when the snows melt, some Hereford cross calves appear and it all ends happily ever after.

I wasn't quite so sure that tears of joy would balance those of grief in Lucky's case, but when I tipped out the empty pot the other day, I was mightily surprised to discover some tiny tubers where Lucky had once been. Even more surprisingly, they were apparently alive. I'm therefore fairly confident that Lucky will get another chance on the roulette wheel of life. I've potted up the tubers and this time I'm making sure I keep sharp hoes well away.

I've also managed to unearth some deep-seated survivors from last year's seedlings, which is heartening. There are at least three varieties here, all born and bred at Oca Acres. The conclusion is ineluctable: the oca planting season is now most definitely upon me and I must marshall my raggle-taggle army of survivors as they wake from their slumber. Once more into the trench dear friends.

It's Not Too Late For Talet

2011-03-28T07:35:00.005+01:00

Last winter was, as people in these parts never fail to mention, unusually cold. My talet seeds sat in small pots, exposed to the elements and were frozen solid for several weeks. I was a little concerned that this might have killed them, so I tipped out the various caches with some trepidation the other day. But, no - they were unharmed and had, in fact, started to germinate. Respect.

If you're not familiar with this excellent plant, you can read all about it here.

Talet has the obliging ability to form the big succulent subterranean seeds that people (read me) like to eat, as well as small hard aerial seeds which are less immediately appealing if you value your teeth, although they're perfectly edible if properly cooked. Their enamel-shattering quality means that they can sit in the soil for years before germinating and this makes them a good life insurance policy for the plant if conditions get tough. They're also pretty handy for the gardener as I've found they'll store happily with minimal attention for years, perhaps decades. You can see the difference in size between the two seed types. Same plant, two types of seeds: amphicarpy in action.

Unlike those big fat ones, the aerial seeds take a bit of persuading to germinate. You need to scarify them prior to sowing; I use a bit of sandpaper to scrape a tiny hole through the seed coat on the edge furthest away from the hilum, the plant equivalent of the navel, which is close to where the root and shoot emerge. That way the delicate bits are protected from my clumsy manipulations and once that hard shell is breached, they usually swell up and germinate fairly quickly.

I have a new variety of Amphicarpaea bracteata to try out this year. Mark Robertson very kindly sent me seeds of a variety sold by Gardens North in Canada. Sounds promising. I'm also going to see whether I can resurrect some I collected from New York State a few years ago. This is what I shall henceforth be referring to as Amphicarpaea bracteata "Saratoga Battlefield", because I collected them at the site where the British under General Burgoyne were defeated by American forces during the War of Independence in 1777. My American companions felt this was an opportunity for some gentle humour at my expense. I smiled and replied, without the slightest hint of irony in my voice, that the British, as the world's top nation at the time and bona fide bloated imperial power, had it coming. They seemed satisfied with that.

If both these new varieties grow successfully, it will be interesting to compare them in terms of vigour, yield and flowering time. The resultant plants will be smaller than those formed from the subterranean seeds, at least initially and will need a bit more cosseting in the first season to ensure that the underground crop matures successfully. I'm happy to devote that bit of extra care to guarantee success. In that case I better get on with it today, so I'm not too late starting the Radix Grand 2011 Talet Trial. Fetch me my sandpaper.

Mecha-meck: In Memoriam?

2011-03-07T08:25:00.005Z

Last year, in a moment of rash enthusiasm, I sowed seeds of mecha-meck, (Ipomoea pandurata) a "hardy" sweetpotato relative, along with those of Ipomoea leptophylla, the manroot. Mecha-meck has a fairly wide distribution along the eastern side of the USA, where winters are usually far more severe than the ones we get here. Manroot is found in the Great Plains region and the high deserts of New Mexico and Colorado, where once again, the winters are much colder than we experience.

Last winter's cold snap has proved a challenge for plants which I would usually consider to be fairly hardy. Mecha-meck has turned out to be a casualty too.

Somewhat cautiously, I tipped the mecha-meck roots out of their pots. Several had disappeared altogether. This is one of the disarticulated cadavers I discovered.
The root resembled sweetpotato in texture, with none of the appeal: the rank smell emanating from its decaying flesh dissuaded me from putting any in my mouth. Wimp.

I am now left with (perhaps) one survivor. I've potted it up and brought it indoors in the hope that it will live to see another summer.

The manroots (menroots?) to the left of the single mech-meck, have apparently fared much better, apart from the odd slug hole. This seems surprising considering their supposed predilection for desert habitats. Not exactly man-sized, they are a bit puny.

All this goes to show that hardiness is a fluid concept and is dependent on more than simple thermometer readings. I suspect that our combination of excess soil moisture, suddenly followed by sub-zero temperatures, simply confused the cellular processes which protect plant tissues from freezing. None of which is much consolation when I think about it.

So whatever else it is, mecha-meck is not as hardy in our slushy, wet and occasionally cold winters as I had hoped. Manroot seems somewhat hardier. As mecha-meck is an obligate outcrosser, the one remaining plant, if it survives, will flower its heart out and still remain barren. Poor thing. But maybe I can snatch some sort of victory from this defeat. It turns out that I. leptophylla and I. pandurata are very closely related, so it might be possible to combine the best qualities (whatever they are) of both species by crossing them. Any seeds developing on the mecha-meck plant would be interspecies hybrids and that could lead somewhere interesting. Or not, of course.

The fact that the high altitude I. leptophylla has overwintered more successfully than mecha-meck suggests that I should continue the hunt for the seeds of Ipomoea minuta, which grows at even higher altitudes. Then there are also those New Guinea sweetpotato seeds, from the chilly highland region. I really ought to try some of them too. Now where did I put them?

The Bulbous Belly Border 1) Cacomitl - The Flecked and Feline Flower

2011-02-23T07:57:00.001Z

There are a surprising number of edible bulbs, which although quite low yielding, deserve a place in the garden for occasional snacking purposes or impromptu feasts. As I pondered on this a while ago, I came up with the concept of planting up a mixed bed of these species: the Bulbous Belly Border. But which bulbs or corms to choose?

Camas is well-known for its edible qualities and is an obvious candidate. But another bulb, the extravagantly exotic tiger flower (Tigridia pavonia), must surely be the dark horse in any race to get bulbs onto your plate. It's a well-known Mexican plant, quite easily grown, with ridiculously large and opulent flowers for its stature. These open in the middle of the day and seem to close just before you get home from the daily grind - a particularly annoying trait in view of their spectacular beauty. Luckily, the flowers appear during the summer over a period of several months, so odds on you'll get the chance to see them in all their glory on a few occasions.

Tiger flower bulbs are often sold in the pile-it-high-sell-it-cheap supermarkets at this time of year, although I wouldn't advise eating these - plant them and consume their progeny after a couple of seasons' detox in your own garden. As plants they're certainly much hardier than received wisdom suggests and the bulbs happily survive the erratic cycles of wet and cold weather that typify our winters here.

For all its gaudy allure, this is a plant that seems to be adept at generating a considerable amount of confusion and misinformation. Tigridia, as is pretty obvious, is derived from the tiger, an allusion to the stripes in the flowers. Except they're not stripes, they're spots. The Aztecs, who knew the plant well, referred to the flowers in Nahuatl as oceloxochitl, which means - no, not ocelot, but jaguar flower. At least both the ocelot and jaguar are spotted New World cats - a definite improvement on tiger. I can only assume that European prejudices about the superiority of Old World felines influenced the decision to elect the tiger Top Cat when bestowing names on new plants.

The bulbs (not corms as is often stated) were a familiar foodstuff to the Aztecs and were known as as cacomitl. This has nothing to do with and should not to be confused with the cacomistle, a raccoon-like animal with which the Aztecs were also acquainted and whose name is derived from yet another Nahuatl word. And to top it all, Tigridia is also a single species genus of Nymphalid butterfly found in Mexico and South America. Thankfully, that does at least have stripes.

Cacomitl bulbs have a pleasant, sweet flavour and floury texture when cooked, quite similar to a sweet chestnut - but don't eat them raw. Like the jaguar, they bite. I was tempted to try one straight out of the ground, but at the last moment, discretion overcame my valour. I would be interested to know what causes the nasty sensation of burning mouth and throat that will surely ensue should you be braver than me. I wonder whether they contain those vicious needle-like calcium oxalate crystals that you find in some other roots and tubers, notably taro. Cooked, however, they're like a lion tamed; I've had them both boiled and baked and they certainly make good eating.

The bulbs produce large numbers of offsets and if you dig up the clumps every couple of years, you can eat the spare ones. Yield and bulb size are not spectacular, but there's something quite satisfying and subversive about converting ornamentals into edibles on the sly.

As might be expected, I'm by no means the first person to explore the potential of cacomitl in recent times. Ken Fern, in his excellent book, Plants for a Future, describes their ease of cultivation and propensity to self-seed in a Cornish garden not so far from my own.

More surprising is Luther Burbank's interest in their potential as a food. Burbank was a prolific plant breeder who developed hundreds of varieties of ornamental and edible crops at his trial grounds in Santa Rosa, California. I can do no better than quote the "Plant Wizard" himself, from his 12 volume 1914 book 'Luther Burbank: His Methods, Discoveries And Their Practical Application'. In Volume 10, Chapter 3, 'Tigridia and Some Interesting Hybrids. New Charms in Faraway Flowers', he has this to say:

The development of the bulbs of the tigridias has not been at all a matter of accident. At all stages of the experiment in hybridizing and selection, I have paid the most careful attention to the condition of the bulbs, selecting always those that were largest, firmest and soundest. And the reason for this was not merely that such bulbs usually produce the best flowers, but also that it is worth while to improve the size and quality of the bulbs quite on their own account.

The particular reason for this is that the bulbs of the Tiger Plant are edible. When cooked like potatoes, or made into a stew, they constitute a really delicious vegetable.

To my taste the bulb of the tiger plant is at least the equal of any vegetable under cultivation. It is also highly nutritious. I am not sure that it has an equal among the vegetables of our gardens in its combination of nutritiousness and appetizing flavor.

No one to my knowledge has ever said that about mashua. Or oca.

Burbank was somewhat of a maverick and his unorthodox approach to record keeping (what records?) did not endear him to the scientists who were at that time making the first forays into understanding the genetic nature of inheritance. He liked to cross plants, sow the progeny by the thousand and cull the inferior ones. Maybe that's an approach a bunch of contemporary cacomitl enthusiasts could take: sowing seeds and selecting for the biggest, tastiest bulbs.

Burbank was interested in Tigridia for both its ornamental and edible qualities, but I'm not so worried about the flowers myself; if they were a quarter of the size and the bulbs four times bigger, that would be, to my mind, an acceptable trade-off. After all, the heart doesn't crave flowers when the belly lacks bulbs.

Another Root Less Travelled: Silverweed

2011-02-03T09:00:00.004Z

Imagine a not-uncommon weed, one which any self-respecting gardener would evict from her garden with alacrity. A bed choking thug, which although short in stature, compensates by spreading sideways with panzer-like rapidity. It turns out that this self-same plant has been helping keep the hungry alive on several continents for centuries. Even more incredibly, it is now doing sterling work in preventing infant malnutrition.

So who, or what is this sinning saint, this sweetpotato of the north? I'm talking about none other than silverweed (Potentilla anserina). Even if you don't know this plant, the chances are that you've walked on it or passed close by.

Image courtesy of www.donaleaplantbrokers.com/

It's a rather beautiful plant, forming low growing tufts, with silkily haired leaves which give it that eponymous silvery sheen. Dotted amongst the leaves, during the growing season, are pretty, bright yellow, five-petalled flowers, which help establish its identity as a Potentilla. This combination of two precious metals on the one plant accounts for a common French name, richette.

Actually, botany's grand panjandrums have seen fit to rename it Argentina anserina, but in the pugilistic world of plant systematics, this change has not gone unchallenged - the gloves are off and it's Round Two. I'm personally hoping that the cocky upstart is decked by a swift left hook and Potentilla is reinstated. I won't cry for you, Argentina.

As the season progresses, silverweed sends out wiry red stolons which root along their length, establishing daughter plants at every node. Large colonies build up rapidly. You have been warned.

I remember my surprise when I first evicted a few small clumps from a friend's garden. Astonishingly, they had long roots. Even more astonishingly, they were slightly thickened, particularly at the ends, in a way that is sort of reminiscent of the Chinese yam (Dioscorea batatas). It was possible, in a state of intense hunger, to imagine how it might be worth harvesting and cooking these roots, in lieu of any other carbohydrate staples. That dog-eared old
copy of Food for Free, whose entry on silverweed I had doubted, wasn't lying after all.

The region of Britain that is most associated with silverweed harvest is Scotland, more specifically, the Outer Hebrides. On North Uist, in a certain place, according to folklorist Alexander Carmichael, a man could sustain himself on a square of ground of his own length. Either the silverweed of Uist is remarkably productive or he meant a single day's ration. Perhaps a kind inhabitant of said island paradise would like to confirm or deny these rumours. If true, would she please send me a specimen of brisgean, as it is known in Gaelic, for further evaluation.

Over on the other side of the world, along the Pacific seaboard of British Columbia, silverweed harvesting was also carried out in an intensive way. Harvesting, frankly, is not an adequate description of the highly organised approach to crop management that was used by the First Nations of this area. Like with the camas crop, this was really horticulture. In fact both species were sometimes cooked together, along with the rhizomes of a clover, Trifolium wormskioldii. Elaborate gardens were constructed, sometimes involving dry stone walls and their ownership was jealously guarded.

To get further information on silverweed and its cultivation and preparation in that area, I contacted Professor Nancy Turner at the University of Victoria in British Columbia. She is a renowned ethnobotanist and has carried out research into silverweed and several other native root crops of the area. Her studies show that silverweed roots have a comparable food value to that of the potato, with the added advantage of higher calcium and magnesium levels. Traditionally the roots were steamed in pits and eaten with an oil condiment, a favourite being ooligan (or eulachon) grease, produced from the shoals of smelt that abound in the area. Some native people have compared the taste to that of sweetpotato. Occasionally the cultivated roots reach a diameter of 7mm, which is really quite impressive. The Pacific silverweed is often classified as a separate sub-species P. anserina ssp pacifica or as P. egedii and is distinctly less silvery than the plant that I know and love.

Abe Lloyd, one of Nancy's students, told me about his research into traditional silverweed gardening methods in British Columbia. Abe has been restoring First Nation silverweed plots that were abandoned about 50 or 60 years ago, using a combination of weeding and tilling. Favoured sites are generally found along estuaries in moist, sandy soil. The traditional tool of choice is a digging stick made of Pacific yew. Yields sound quite good to me: about 710lbs per acre according to Abe, this being an average from the 60 plots he managed as part of his MSc project.

All this may seem to be a sufficiently ringing endorsement of silverweed to send you scuttling to nearby gravelly river banks or estuaries in search of it. But no, there's more. High up on the Tibetan Plateau, droma, as silverweed is known, is being incorporated into the barley-based diet of young children. Silverweed's amino acid profile complements the barley's and creates a complete protein, presumably supplying the lysine that the barley lacks. In any case, the Terma Foundation has been promoting a return to silverweed consumption as a way of ensuring that the next generation of Tibetans are strong and healthy. It's a common plant there and as the name Potentilla suggests, it also has medicinal uses.

Silverweed is one of those foods which the potato (damn its eyes!) seems to have driven from our plates out to the badlands, with the status of vegetable pariah. Perhaps it's time for reacquaintance and re-evaluation. So, in the spirit of enquiry, I decided to investigate further. Last spring I collected some silverweed shoots from a few locations and potted them on. I left them alone pretty much thereafter, apart from watering them.

I also had my eye on a wild stand, growing, true to type, by the water's edge in gravelly soil. The plants die back quite early in the autumn, so I headed out while the leaves were still visible. Armed with a trowel and a bag, I set about excavating the plants and their roots.

Initial yields were puny: I discovered that the densest growth at the centre of the clumps produced no thickened roots. Dispersed clumps proved to be more rewarding. It was easy to see how the very act of harvesting, with associated disturbance and thinning, might benefit the harvester by reducing competition between the clumps.

Encouraged by my success, I went home and harvested the potted plants. This is how the roots looked after I'd cleaned them.

So what did they taste like? I took the largest of the roots and boiled them for a few minutes. They had a starchy, somewhat nutty taste, with just a hint of bitterness. I was surprised to find that they were, as our ancestors knew, perfectly suitable for eating.

So silverweed may really deserve the precious allusions its name conjures in the mind. It's frost hardy and easy to grow; it's certainly vigorous. It is even, to my mind, an attractive plant too. The roots may diverge a little from the bulky ovoid shape typified by the potato, but that doesn't seem to have hindered spaghetti's adoption as a common foodstuff. Silverweed's roots are thicker than spaghetti strands, have their own flavour and are nutritious. With a bit of selection for taste and yield, this could be an interesting low maintenance crop for adventurous gardeners. The first step is to locate superior wild strains. That's where you come in. If you've got a digging stick and time on your hands, you can help me find the finest silverweed varieties for yet another Radix breeding programme. Tempted?

Cleaning Up My Act; Radix is Two Today

2011-01-18T07:45:00.004Z

It is very uncharacteristic of me to restrain myself from opening my Christmas presents until this late in the year. I've always considered delayed gratification to be one of the most overrated virtues and have acted accordingly.

So how I managed not to harvest my indoor ulluco plants until now is nothing short of remarkable. I wish the same could be said of the yields I obtained. Ulluco does seem to be infuriatingly fickle: it doesn't like to be too hot or too dry and slugs seem to enjoy it more than the average ex-pat Andean tuber crop. Then there's its steadfast refusal to form tubers at anything like a sensible time of year. That's why, in sheer desperation, I've taken to growing it on the windowsill in a cool room. Hopeless - but oh, those tubers are so exquisite.

Another black mark against its name is its susceptibility to viruses. Virtually all the plants I've seen are loaded with viruses. Which brings me on, rather neatly, to a post which I was intending to publish on ulluco last year, but didn't, for reasons that will become obvious:

Cleaning Up My Act

Not the brisk rub down with carbolic soap that some have suggested I need, but more of an attempt at a bit of in vitro cultivation of ulluco, that iconic Crap Crop of the Incas. The intention of the exercise is to see whether its crap cropping might be ameliorated a tad by eliminating all the nasty viruses that lurk inside both tubers and plants. I've enlisted the help of a friend employed at a local institute of learning - let's call him "M" for the purposes of this post. He's got the requisite technical skills and is keen to help. He's also pretty nifty at fixing gadgets, cars and assorted technical paraphernalia. Maybe "Q" would be a better name: my Aston Martin has never run so smoothly......

This is a virus laden leaf of Ulluco "Cusco Market", with blotches of some sort of mottle virus clearly illuminated by the light behind.

Like potatoes, this is no good at all for the plants and reduces their vigour. Weak plants give reduced yields; in the case of ulluco this frequently leaves you staring blankly at the empty soil in disbelief, like a horticultural Old Mother Hubbard. Viruses are the bane of tuber crops and should be driven from their hosts and put to the sword at every opportunity. Like now.

There's a well-established protocol for this in some Andean root and tuber crops, but firstly we opted for the squint and slice method, which involves the removal of the miniscule growing tip of the plant, known as the meristem. This is usually virus free, as the cells are dividing so rapidly that they outrun the viruses. If said meristem is placed in a sterile growing medium with the right levels of plant growth regulators and vitamins -bingo - you get a new virus-free plant. That's the theory anyway. At least we now have the plants growing under aseptic conditions - the Andes in aspic if you like.

Here are some ocas:

These are ullucos:

Viruses can be defeated in other ways, including the addition of antiviral compounds into the growing medium (which is usually agar based) or by subjecting the plants to higher than usual temperatures, which zaps the viruses, but leaves the plants themselves unharmed. Being of a cautious and sceptical demeanour, I decided that we should, in addition to meristem tip culture, attempt at least one of the other options to give those vile viruses a double whammy that would surely leave them homeless............ Communication ends here.

In one of those charming little volte-faces, I lost all of the above plants when I opted for an impromptu stay in the local infirmary. At that precise moment (and not a million miles away) the incubator where the plants were stored chose to fail; the combination of several weeks darkness and low temperatures killed the whole lot. I almost cried when I finally managed to struggle in and survey the carnage.

Tissue culture of plants is not that difficult to do (I managed it) and can be carried out quite successfully at home, using bleach, a pressure cooker and a few other bits of equipment. Sinner, lay down that Sabatier and pick up your scalpel. So although this experiment ended in failure, I have at least shown that it can be done - should be done.

Oh, and by the way, today is Radix's second birthday. The "terrible twos" await. No one ever said this was going to be easy.......

Ocabliteration?

2011-01-05T08:40:00.004Z

The cold snap has abated and 2011 is here. Time to see what effect some exceptionally cold weather has had on the poor old ocas, which I was unable to lift at an appropriate time. I fear the worst. Now it's time to see whether those fears have been realised.

I spent a pleasant few hours on my hands and knees at Oca Acres the other day, rescuing what remains of my oca crop. There's something truly life affirming about plunging one's hands into icy, wet soil. Maybe the pain it causes reminds me that I'm still alive and this isn't a nightmare, it's real.

Avid readers will know that I've been using open-ended pots plunged in the soil to enable me to pack more plants in while keeping their tubers conveniently separate. I had reckoned without the ferocity of the frost, which seems to have penetrated all above ground soil or compost located in pots, with predictable results for any frost sensitive plant structures.

To compound my annoyance, those plants with nice, tightly clustered tubers around their stem base have taken the worst hit of all. Let's just say that I'll be adjusting my growing methods in future. I can see two options:

1) Harvest at a reasonable date before the onset of hard frosts, say the beginning of November.

2) Find another site where I can conduct trials on a more appropriate scale, without recourse to pots.

The third possibility, to disappear on the back of water buffalo and forgo any further contact with humanity (or alternative root crops), is currently in reserve if I mess up again.

Here are some of the tubers from seedlings raised in 2010. Many other quite promising looking ones have been reduced to mush, unfortunately. I don't think any taste testing will be going on this year.

I rather like the shape and colour of these.
To the best of my knowledge, neither of its parents had this tuber colour, but the riotous pollination free-for-all back in the heady days of 2009 makes it impossible to be sure.

Due to differences in pot configuration, location and maybe some other unknown factors, all the tubers from my reference collection, along with the tubers from last year's seedlings have been frozen - they are all dead. This is kind of like last year, when a spell in intensive care prevented me acting opportunely to harvest the tubers, only worse; I pulled through that experience, as did most of my ocas, but this lot won't. When you see the words "crop failure" in a seed catalogue, this is what it means: wailing banshee growers condemned to wander in a twlight world, their spirits unable to rest.

Actually, I'm bloodied but unbowed. I'm reminded of Galvarino, the 16th century Mapuche folk hero, from Chile. Captured by the Spanish invaders, both his hands were chopped off and he was sent home to his compatriots as a warning. Undaunted, he returned to fight again, with two knives strapped to his wrists in place of his missing appendages. The interwebs describe his attitude as "badass". Following his never-say-die example, I will rise again, a trowel in each hand and crack the small matter of locating a day neutral variety of Oxalis tuberosa. Up from the ashes grow the ocas of success. Happy New Year.

Merry Ulluchristmas

2010-12-22T11:07:00.001Z

At last I think I've found a future for ulluco: not as a crop, but rather as an edible Christmas tree substitute. The plants look quite attractive with their glossy foliage and brightly coloured baubles hanging from slender threads. Very festive. Or at least they would if I had taken a little bit more care of these windowsill specimens and kept them them neat and tidy. I've done it in previous years and the effect was quite good when I kept one on my desk. The tubers eventually go green, but are still edible if required and seem to make good tough stock for planting in the spring.

One thing I did discover this year was that two of the other varieties (not shown here) seemed happy to tuberise successfully at fairly cool temperatures under a prolonged daylength regime of about 14 hours. The next step, obviously, is to try and cross these two and produce true ulluco seed. The question is: are they diploid, triploid or just plain debilitated? That's something that will have to wait until 2011 for distended stomachs to contract, inquisitiveness to return and days to lengthen. Merry Christmas.

Ice Cold at Oca Acres

2010-12-06T07:27:00.017Z

Oca Acres is well and truly frozen. Unlike Marvin Gaye, who famously heard it through the grapevine, I wasn't really as aware of the seriousness of the impending plunge in temperatures as I should have been.

Forwarned is forearmed; complacent gets a kicking. So, like last year, I have been caught out with my ocas unharvested. Whether this surprisingly precipitous start to winter is connected with climate change, I have no idea, although the loss of Arctic sea ice has been implicated in last year's cold snap. Then there's the not inconsequential matter of the North Atlantic Oscillation. Rather than spend the rest of my days struggling to interpret climate science, let's just say that my plans to plant an avocado orchard may be on hold for a while. Shame, as I like avocados.

Me and Marvin share this much in common: I'm concerned that I'm bout to lose my mind over the whole business. I wonder how deep the frost has penetrated. I wonder how much longer the cold weather will continue. I wonder how many tubers will survive and how many will be lost. I've built up a collection of over 140 genetically unique oca varieties; to part with it through what might be characterised by the less-than-charitable as negligence - now that would be truly shameful. And this year I can't plead extenuating circumstances, other than my innate indolence. The secret of good comedy, is, so they say, timing. This must be even more true in the case of gardening. Due to other commitments, I let things slide and may now be paying the price.

Rather than an exercise in grovelling self-abasement and an attempt to elicit sympathetic comments on my blog, I see this as strong reinforcement of my gut instincts. It is clear that I need to decide a cut off date for the oca harvest, as I've previously considered and then stick to it. The beginning of November seems appropriate in this area. This would also allow me to sort the good-doers from the no-hopers in a systematic fashion: I could weigh them in the balance and those found wanting could easily be eliminated through our digestive systems. But if you feel like sending me your comiserations and condolences, don't let me stop you. Love me, pity me, but don't ignore me.

As I won't be able to harvest the tubers for a while yet, I draw some comfort from this little packet of oca seeds, the product of pods picked in haste before the first frosts. Lacking the necessary slaves to record their parentage in painstaking detail, I opted for the happy, mixed blend approach. I like to think that there is strength in diversity and that the alleles for the very necessary day-neutral tuberisation response are lurking in there somewhere.

Mauka: Mission Accomplished

2010-11-22T21:56:00.000Z

Determination, vision and a piece of black plastic have shown that mauka anthocarps-a-plenty can be produced right here, right now. These are the ones that I've collected from the white flowered variety "Blanca" which Frank van Keirsbilck sent me last year as a cutting. If they turn out to be viable, which is my fervent hope, breeding better adapted maukas should be within my grasp. Or I should at least be able to breed ones which are equally as good as the existing ones. In the light of the successes Radix has also experienced with oca seed production, I am now envisaging a two-pronged attack on Britain's vegetable gardens in an attempt to overthrow the centuries-old hegemony of Solanum tuberosum, followed by a pincer like movement across mainland Europe. The revolution begins here.

OK at the Oca Corral?

2010-11-15T09:15:00.003Z

I think I may have given the impression that all my ocas were killed back in October. Actually, that's not strictly true. By happenstance, I had covered up some late-maturing chillies with horticultural fleece. This billowing gossamer drapery offered them sufficient protection throughout the cold period in October, when several hard frosts coincidentally destroyed the flower (literally) of my oca crop. Then, the other night, it did what fleece so often does - it blew away in the gales, exposing the chillies to the frost which followed. I hate those fleeces to pieces!

Still, this gave me an opportunity to take a look at some of the self-sown oca seedlings which had appeared, if not in profusion, then with a surprising frequency amongst the official crop. Conditions were not ideal, what with shade and competition from the chillies. Nevertheless, some of these intrepid interlopers had made a reasonable amount of growth. The frost had put a stop to that, so I decided to take a look at what the situation was on the ground, or rather, below the ground.

It quickly became obvious that the diaphanous polypropylene sheet had done more than offer a refuge to the plants. The friendly neighbourhood voles had been enjoying the warmth and protection provided; with typical microtine gratitude they had launched a preemptive strike on the swelling stolons, severing them before they had a chance to metamorphose into tubers. In some cases they had bitten through the stems of the plants as well. Little piles of julienned tubers were scattered around.

Ah, the perils of stochastic events, the term by which these sorts of randomly fatal happenings are apparently known in population ecology. I notice that Bob Dylan opted to substitute 'stochasticity' with 'a simple twist of fate' in the song of the same title, presumably due to the enhanced lyrical flexibility gained by so doing. Or maybe he don't know much about history, don't know much biology. If you're out there Bob, tell me whether you can throw any light on the four year cyclical variation in vole populations and its effects on my horticultural operations. Might make a good song.

But not even the voles had quite managed to eliminate the brave ocas and their plump, perennating propagules. So, to all the naysayers and doom mongers out there: this plucky Andean underdog - oca - has shown that it has the smarts to scatter its own seeds, survive rodents, slugs, incompetent gardeners and then produce a crop of tubers in one season. OK at the Oca Corral? Yes, I think so, definitely.

As proof, I offer these pictures of some of my very first self-sown oca plants. Had the frosts held off until this time, as is usual hereabouts, I'm sure they would have done perfectly well without protection.

Mauka - Pregnant With Possibility

2010-11-04T22:02:00.001Z

Is that an anthocarp on your inflorescence or are you just pleased to see me? Mae West's opinion of obscure root crops is, as far as I know, unrecorded, but I like to think she would have taken full advantage of the innuendos that lurk in the seedy, fecund alleyways of horticulture. Pricking out, for example, could hardly have escaped her attention. That, in conjunction with hardening off, would surely have led to the genesis of some memorable one-liners, all delivered in Mae's signature drawl.

In any case, it seems as though my patented mauka floral induction protocol has yielded the desired results, or soon will, all being well. There are several significant swellings appearing on both Blanca and Roja plants where the flowers used to be. I don't know whether my casual floral fiddling has anything to do with it, but they seem to have been pollinated somehow, by something. Yes, Mae, those really are anthocarps on their inflorescences and I'm certainly pleased to see them.

I decided to break with tradition and follow my own advice for once - I brought the burgeoning blossom bearers indoors as temperatures dropped. They have been sitting on a windowsill for several weeks now and have thus avoided the cold snap that hammered their outdoor compatriots.

Image courtesy of Frank van Keirsbilck

Coincidentally, Frank van Keirsbilck recently sent me news of his own mauka crop. An image will spare you the necessity of extraneous descriptive prolixity on my part, so I'll say no more than this: 3 kilos.

The Iceman Cometh

2010-10-26T22:08:00.001+01:00

I enjoy a crisp autumn morning as much as the next person. Except that I don't, or at least I recognise that there's no pleasure to be had without pain. A crisp autumn morning means only one thing for the grower of late-maturing Andean root crops - frosted plants. My fervent wish was for a few more weeks of life for my plants; that wish has not been granted. I'm not exactly choking back the tears, but I can't pretend that I'm anything less than disappointed.

Looking over Oca Acres this morning, it is easy to see the devastation that has been visited on the ocas, mauka and yacons. The latter are blackened, with the shrivelled yacon hybrid flowers hanging limply from the stems; the maukas have not just been nipped by frost, but have apparently been been frozen to the roots; formerly lush oca plants lie slumped, with eerily bleached stems seemingly drained of blood, like the victims of a vampire attack.

I won't dig the ocas up just yet. I 'll probably wait a while, so that the dying stems can pump their last vestiges of life force down into the tubers, which should be forming by now.

I say "should be forming" advisedly. Reduced daylight hours, low temperatures, low intensity sunlight - that's a recipe for disappointment if you're hoping that your tubers will bulk up quickly at this time of year. Guaranteed.

All crops can fail; all crops do fail. The knack is to reduce the odds of failure to acceptable levels. And yield ought not to be a dirty word when growing a crop of Andean tubers. The remedy is simple, although not easy: breed better adapted varieties, that are actually fit for purpose at our latitude and are able to tuberise during the summer. That's the magic, not silver, bullet I'm looking for.

I'm hoping that this year's seed crop will be sufficient to enable me grow yet more seedlings next year. I'm also hoping that I'll be able to share some seeds with the various TOSsers who've expressed an interest in taking part in Project Oca. One thing's for sure, there'll be no more oca flowers, seed pods or seeds from my plants this year.

Yacon - The Kentish Connection

2010-10-18T10:15:00.001+01:00

That gladiator's net is closing on the mystery of the yacon hybrids. Frank van Keirsbilck told me that the unidentified pollen parent was a Smallanthus that came from seeds provided by Ulrike Paradine. These were from plants that have been growing happily for a number of years in her garden in Kent. I contacted her and she kindly gave me a few more pieces of information and some pictures of her plants. Cop a look at these:

Image courtesy of Ulrike Paradine

There's no mistaking the similarity of these images to the yacon hybrids. She collected the seeds (OK, you pedants, cypselae) herself in Costa Rica. I did a bit of intensive interwebbing and my trident speared three possible candidates for this unfolding paternity suit:

S. latisquamus

S. maculatus

S. riparius

All three species are found in Costa Rica. So far, so good. Of the three, S. riparius is found from Central America to Northern Bolivia and is considered to be similar to and maybe able to hybridise with, S. sigesbeckius, one of yacon's putative ancestors. So, as far as I'm concerned, it's a possible thumbs up for S. riparius as our mystery species. Or, as toga party afficionados will never cease to explain, that should actually be a thumbs down. If anyone out there with first hand knowledge of the genus Smallanthus would like to chip in, please do. I could be wrong. I usually am.

More interesting information from Ulrike: the plants regularly set seeds in Kent and not only that, she has had self-sown seedlings appearing from time to time. Her plants have often overwintered outside in her garden. They don't have the big storage roots of yacon, unfortunately. Despite this, these strike me as exactly the kind of robust, sturdy, adaptable traits we need to incorporate into the Radix yacon breeding programme. You didn't know there was a yacon breeding programme at Radix? There is now.

Tussling With Talet

2010-10-11T07:00:00.038+01:00

In the polyculture cage fight currently raging across my oca bed, it seems like the talet (Amphicarpaea bracteata) is winning.

A couple of the subterranean talet seeds popped up amongst my oca seedlings in the spring and in an act of sentimentality, I decided to allow them leave to grow. I was also curious to see how the two plants would co-exist. Now I know.

Oca is no slouch when it comes to suppressing the growth of other plants, but it seems to have met its match in talet. This plant could qualify as Cornish kudzu.

The talet is straddling the ocas at a height of about a metre and has now begun flowering profusely, presumably as a response to shortening daylengths; pods will surely follow. The aerial seeds are small and hard and although perfectly edible after boiling, they lack the big fat wow factor of the subterranean seeds.

As it is above, so it is below - hopefully. Parting the dense mat of oca stems and foliage, there's ample evidence of rampaging talet shoots, each bearing a single cleistogamous flower at its end. These pollinate without opening and then burrow into the soil where they swell into nice rotund beans, assuming the slugs don't graze them off first. Like oca, they're frost tender, so, in theory at least, it would be possible to harvest both together when they've succumbed to the cold. If your enthusiasm for plunging your hands into frozen soil begins to wane, I'm wondering whether a couple of chickens might enjoy scratching around for the seeds while you wait for the feeling to return to your fingers.

So there you have it, a vigorous nitrogen-fixing groundcover which produces delicious beans - it should surely be on the wish list of all aspiring polyculturists. Free machete with every packet.

Mauka: Man Bites Dog

2010-10-04T07:00:00.002+01:00

Being baffled, mystified and bemused is my usual state when it comes to dealings with Inca root crops. This is nothing new and is, frankly, hardly noteworthy. Dog bites man - big deal.

But I'm now happy to reveal that in a spectacularly organised and executed ruse, I've managed to trick some of my mauka plants into flowering. Man bites dog - interesting.

Those with long memories and limited social lives may recall that I managed to produce a single seed - whoops - anthocarp, from a mauka plant which, like me, spent most of the winter staring out the window.

Winter is a singularly unpropitious season in which to expect most plants to flower and set seed. I determined, therefore, to see whether some cutting-edge daylength manipulation technology might have the desired effect at a more favourable time of year. Following a period of reflective procrastination, during which I pondered on the practicalities of said undertaking for about a month, I leapt into action. At the end of July, I started the procedure by religiously wrapping the plants in black plastic at 7pm and shoving them into the back of a shed until 8am the following morning - vespers and matins for mauka, you could say: thirteen hours dark, eleven hours light. There was a fair amount of genuflection, what with all the wrapping and unwrapping and fitting the pots into the available space.

Throughout this ritual, as I had expected, the plants seemed sublimely indifferent to my actions. I continued the process, day in, day out, until the end of August, when my trip to Belgium interrupted play. I shrugged my shoulders and left the plants outside to face ambient daylengths and light levels.

Now, both 'Roja' and 'Blanca', the two varieties Frank somehow magicked out of the air in 2009, are showing flower buds. Blanca has just started flowering, in fact. I think it wins the runner-up prize in the Ullucus tuberosus Challenge Cup for the least inspiring floral display in an Andean root crop. Strange, considering how impressive Mirabilis jalapa flowers are. I'm not bothered though, as long as it forms some viable anthocarps.

I now realise that I should have started this experiment earlier, about the time of the summer solstice, but there may yet be the possibility of seed formation, especially if I bring the plants indoors to speed up the process. I can only assume that my efforts are responsible, as the other mauka plants, spared the early bedtime, show no indications of any flower buds. That includes specimens of both Roja and Blanca.

If this simple, albeit somewhat tedious, process proves to be a reliable way of inducing flowering, it should be possible to start crossing varieties and selecting the progeny for favourable characteristics. For that, I'm happy to get down on my knees and face towards mauka on a daily basis.

Yacon: I am Spartacus

2010-09-27T07:27:00.007+01:00

I was shaken out of my complacent, smug, yacon breeder's love-in with Frank van Keirsbilck when I received a worrying email from him some days ago. His yacon seedlings have begun flowering and he is now concerned that a bit of inadvertent cross-pollination with another, unidentified Smallanthus species, may have taken place. It could be that the so-called yacon seedlings are impostor hybrids.

In support of this claim, Frank cites a lemony scent to the flowers and an overall general unease about their "gizz". That and the fact that he might have transferred the pollen from the unidentified crop wild relative while he was carrying out hand pollinations.

Actually, part of me is delighted by this news - that genes from another species may have been incorporated into yacon's genome. This is, after all, the reason plant breeders scour the globe, concocting mashups and fiddling with their GIS in order to locate drought, cold, heat and disease tolerance genes in crop wild relatives.

The other half of me is dreading the discovery that, in addition to all those potential benefits, they'll have inherited a less endearing trait common to most other Smallanthus species: the lack of big, fat storage roots. I fear that some embarrassing and credibility-reducing retraction will have to follow and my reputation amongst my peers will be mud.

My plants have just started flowering and following Frank's revelations I decided to take a closer look. I can't pick up that lemony scent Frank describes. This could be a result of a phlegmish cold I picked up in Ghent and which seems to have dulled my sense of smell. Olfactory limitations aside, there are some noticeable differences.

Left to right; white, "morado", "yacon" seedling

Leaf shape is, well, different, more toothy and feral in the seedlings than true yacons.
In fact, they remind me a bit of bearsfoot aka leafcup, Smallanthus uvedalius, a North American wild flower, with a wide distribution - but only a bit. Maybe they look like one or other of yacon's putative parents such as S. macroscyphus or S. siegesbeckius.

Looking at the stems and petioles, both species seemed to have perfoliate leaf bases and winged petioles. This is the standard white variety on the left; the "yacon" seedling is on the right; the jury could be said to be out on this feature. I don't happen to have access to a Smallanthus monograph, so I don't know whether the winged petioles are found in several species or are a diagnostic characteristic of yacon, S. sonchifolius.

One very obvious difference is that ray florets and at least one whorl of disk florets seem to be open at the same time. You may not be able to see it, but believe me, it's true. That ain't right for yacon - the literature says so.

Looking more closely, I've noticed another striking deviation from accepted yacon wisdom: damn me if they aren't setting seeds, which is something else Frank has also noticed. That's not normal yacon behaviour, so I can only conclude that these aren't normal yacons. As to what they are, I have no idea as yet. Curiouser and curiouser.

So now when I look back and forth between the true yacons and the lush growth of the impostors, I recall that memorable scene at the end of the film Spartacus. In a show of solidarity with their leader, the other slaves claim, one by one, that they are Spartacus and in an act of splendid collective suicide are all crucified along the Appian Way. I doubt whether the A30 would make an acceptable substitute, but Smallanthus does sound a bit like a trident and net-wielding Thracian. It matters little: if I lift them in due course and find they're all tops and no tubers, they'll soon be pushing up the daisies.

Oca: Where Have All the Flowers Gone?

2010-09-13T07:34:00.004+01:00

Over at the Radix Root Crops Facebook page, we've been gathering data on when and where oca plants have been flowering this season. No need to be dragged into the social media maelstrom to contribute - you can post comments here on how your ocas are doing. Then again, if you'd like to chip in - please do so.

It certainly appears that, with the right combination of stylar morphs, it is not too difficult to achieve pollination and seed set in Oxalis tuberosa. But first you've got to get the plants to flower. That seems to be a little bit more challenging.

I derive no pleasure from reporting that, with the exception of Ian at Growing Oca's early flush of flowers in June, I seem to be the only person I know who has had flowering ocas so far this year. In this area of the planet, at least. I would be delighted if you, dear reader, would be so kind as to prove me wrong.

Some of my plants have been flowering for several months and are forming pods. Indeed, I have been collecting ripe seeds for some weeks already As flattering as it might be to promote myself as a horticultural genius, I'm really not some sort of oca uber-propagator. No, some other factors must be involved in my success. The question is, which ones?

One observation is that big, tall, leafy plants with thick stems seem to come into flower more quickly than those which are smaller. As usual, there seem to be exceptions to this rule. Some of my more majestic specimens now have stems of close to a metre in length. Seedlings with small leaves and short stems, like the one to the right of this picture, seem to be showing no intention of flowering. I really ought to uproot them immediately, but I'm hesitating; not a case of clemency so much as curiosity: I want to know whether these scrawny runts will perk up when short days come. Then I'll kill them. Any oca plant that can't enjoy our long balmy summer evenings really has forfeit the right to continued existence and must be catapulted to that heavenly altiplano wherin its ancestors dwell. Alternatively I might just eat them.

Another observation is that seedlings seem to flower more profusely and earlier than tuber-derived plants. This could be due to the debilitating effects of accumulated viruses, or a genetic tendency that only surfaces when the plants are grown from tubers - somehow linked to physiological maturity of tuber-derived plants; a similar phenomenon is often found in seedling potatoes versus their tuberous brethren.

Ian at Growing Oca suggests that rather than size, rate of growth might be a contributory factor. Some of his plants started flowering during a period of moist weather and mild temperatures, then the hot weather and water stress set in, the plants were stunted and no more flowers were produced. Could be. I've certainly noticed that flowers on some seedlings seem to abort in the bud stage more readily than others. I haven't the faintest idea why.

If my experience is anything to go by, daylength doesn't seem to be an overriding factor, as some of my plants began flowering way back in June, when days were about as long as they ever get.

My understanding is that in the Andes, oca plants grow, flower and then die back to the tubers: they complete their whole life cycle before harvest occurs. Here, the plants seem to continue growing during declining daylengths until they're zapped by frost. As enjoyable as it is to be harvesting tubers so late in the season, yields are often disappointing. My guess is that very short days, low solar intensity and low temperatures are not conducive to producing bulky crops of tubers. No, we need ocas that tuberise at a more appropriate time of year. Whether flowering, which in potatoes is usually associated with the start of tuber formation, is a similar indicator of incipient tuber development in oca, I don't know. My plants have got so big and lush and tangled, it's virtually impossible for me to tell.

One final observation: I noticed yesterday that one of the self-sown seedlings has, in the axils of its leaves, the first signs of flower buds. Whether or not these will develop and flower before winter comes, I don't know, but it is at least indicative of the possibility of sowing oca seeds directly and standing a chance of securing another seed crop.

So to conclude, my oca flowers haven't gone anywhere - they're still being produced in large quantities. I'm just a tad perplexed that no-one else has been so lucky.

Rambling Radix

2010-09-07T19:50:00.000+01:00

Travelling from blessed Cornwall to Belgium in search of flowering ocas sounds a bit excessive. Maybe, but like Robert Johnson, I had ramblin' on my mind. I blagged my way onto a conference bash in Ghent, then pimped me a seat on Eurostar to get there. This was, perhaps, marginally preferable to riding the rods on the Wabash Cannonball, the default mode of transport for any self-respecting dishevelled hobotanist like me.

The mistaken assumption that the weather was set fair proved to be just that - a mistake. Sandals and no waterproofs compounded the error. Heavy rain and umbrella-eviscerating winds seemed to have followed us from Cornwall; the latter was, by this time, basking in late summer sunshine. Tant pis.

After a couple of days of soggy wandering around the city, sampling the chocolate, beer and mayonnaise-smothered French fries, I felt sufficiently emboldened to pursue my real motive for the journey - a visit to Frank van Keirsbilck. Frank is a plant explorer and enthusiastic disseminator of ethnobotanical delights and he lives a short way from Ghent, in Scheldewindeke.

A twenty minute train ride took me across the pancake-flat East Flanders plain to Scheldewindeke. Large crops of maize and nursery plots of ornamental trees dotted the landscape; the edges of the track were home to vast thickets of frothy-flowered Japanese knotweed. The Cornwall Knotweed Forum would be apoplectic.

Ambling from the station, I noticed numerous maize cobs infected with Ustilago maydis, corn smut, which produces strangely distorted galls where the cobs should be. Unlike ergot, these are actually edible and tasty and are considered a delicacy in Mexico, where they are known as huitlacoche. Apologies for the picture - it was raining heavily and blowing a gale at the time.

In my haste to catch the train, I had forgotten to bring Frank's instructions with me, so I spent some time wandering along his lane, soaking up the ambience, along with the frequent rain showers. I asked for directions from one of his neighbours and, in lieu of English, which everyone supposedly speaks here, we conversed in French. Actually, he said something and I caught the words "cheveux longs" and la-bas", which with the aid of a directing forefinger led me to a pan-tiled, solar panel clad house hidden amongst trees 150 metres or so away.

Frank greeted me and took me straight off for a tour of his bit of Flanders field, which consisted of patches of all sorts of plants in all sorts of combinations all surrounded by heavily cropping fruit trees. It had been a hard summer, with temperatures up to 35C for several weeks and no rain for a protracted period. This had produced a predictably catastrophic result on some of Frank's precious plants. They had been stunted and shrivelled, some unto death. A particularly sad loss were his ullucos - all gone. A small compensation, perhaps, was a tiny plant of an ulluco variety called 'papa posa' that I had brought with me. I got it from Frank, who got it in turn from Tom Wagner when he visited Europe last year. I also gave him a miniscule cutting of one of my favourite chillies, 'rocopica' (said to be Capsicum cardenasii var pendulum) which grows and fruits well in sunless spots.

Back to Frank's garden; the rain had finally returned to Flanders (yes, I'd noticed) and those plants which had survived the full force of the pitiless Belgian sun were beginning to recover following a couple of weeks of steady downpours.

His ocas showed no outward indications of any flowers, although I thought I saw some tiny embryonic buds nestling in the tops of a couple of plants. At least they were still alive, including a whole load of plants derived from seed I'd sent earlier in the year.

I was particularly taken with his novel crop combination of yacon, mauka and sweetpotato, to which the accompanying picture does not do justice. Here's the idea: the yacons tower loftily above the intermediately-statured maukas and the whole is finished off by the creeping stems of T65 sweetpotatoes. All could probably be harvested in one fell swoop and are sufficiently different in appearance to be easily distinguished after lifting: polyculture just got a whole lot more interesting.

Due to the severity of the summer, the yacons were not as lofty as might have been expected and the other two were commensurately smaller as well, but the idea's certainly worth investigating further. As for a name for this configuration - how about los tre amigos, seeing as three sisters and three brothers are already spoken for.

I was also impressed by Frank's Amphicarpaea bracteata plants - one variety was already producing flowers, whereas my own plants remain steadfastly vegetative to date. Frank told me that the plants have pretty much naturalised in his garden and there were certainly a number of vigorous clumps in various locations.

There were many other delights, but lest I wander completely off task, I'll concentrate on the roots. As we sat over a leisurely lunch of homemade bread and herb tea, by a slight of hand, Frank produced some potatoes from brown paper bags. Blight notwithstanding, I do like the outrageous diversity of potatoes one can grow. These definitely looked interesting.

My notepad was a bit damp by this stage, but I think the top variety was called 'puka quitish'; the other I'm not sure of. They're certainly andigena types.

When Frank proffered some Maori potatoes as well, I thought it ill-mannered to refuse. Judging by the success (not) of our heritage grow-out this year, I feel duty bound to re-home all of them at some stage rather than sacrifice them to death by blight - Phytophthora will be found engraved on my heart.

So I left Frank's with more than I had when I arrived, which is always a pleasant sensation. I am able to report that no ocas were flowering in this part of Belgium in late August and I'm hoping that fruitful exchanges of plants and ideas will continue between us in the years to come. I call that a successful trip. I took the train back to Ghent and to celebrate, headed out to a convenient eatery to experience another local speciality - wafel met slagroom. Delicious.

Yond Yacons Have a Lush and Leafy Look

2010-08-30T07:00:00.006+01:00

The yacon seedlings I planted out several months ago have made steady, though not spectacular, progress. I attribute this to their emaciated state at the time of planting, the cold, dry weather we had thereafter and the lack of space I was able to give them. Excuses over.

Height about 1.5m

With better growing conditions, I'm sure they would now be towering above me, probably studded with flowers and magnetically pulling passing posses of hoverflies and bees. Dream on. They are, however, showing a healthy crop of leaves and have finally taken over the bed in which they were planted with the correct yaconly aplomb.

My seeds, you may remember, came from Frank van Keirsbilck, who managed to secure a crop last year. He must dwell in what is, compared to here, some kind of Belgian banana belt, with wall-to-wall sunshine and soaring temperatures. At least that's how I imagined it as he described the weather in Flanders, last August, while in Cornwall, we sulked under a pall of cloud, mist and drizzle. Seed set here was, unsurprisingly, zero.

I am satisfied, however, that yacon breeding here in Europe's Wild Wet exists within the rootin-tootin realms of distinct possibility. Further east, on the outskirts of London town, Ian at Growing Oca has had yacons flowering for several weeks now, although only of one variety - yacon is said to be an outcrosser, so you really need two varieties that flower at the same time. So far, Ian's second variety has failed to oblige. Yacon has a simple, yet somehow, dastardly, incompatibility mechanism - the disk and ray florets are different sexes and are ready at different times. Because the females, located in the ray florets mature first, before the boys in the disk florets can produce their pollen, it is hard for self-pollination to occur. Good news for genetic diversity in yacon, bad news for would-be plant breeders.

I was all ready to bemoan the strictly stunted and non-reproductive status of my yacons, when I noticed some flower buds nestling in the tops of one of the seedlings. It's only the end of August, so maybe there is still time for a spectacular display and a healthy yield of those coal-black yacon pips that Frank produced last year.

Radix Reaches Out

2010-08-23T07:05:00.000+01:00

My rooty monomania seems to know no bounds. First step to world domination is to gather around you a bunch of fellow conspirators. Maybe I mean megalomania. In any case, I am cordially inviting those with an interest in alternative root crops and social media to join my Facebook group: Radix Root Crops. My hope is that this will provide you with the opportunity to escape my purple prose and act as a platform for sharing the good, bad and indifferent experiences you've had with growing (and breeding!) oca, ulluco, yacon, mashua, hopniss and the myriad other neglected root and tuber crops: there is much to be learned.

So my first question is - who's got ocas flowering at the moment and (even more importantly) who's got seed pods forming - h/t Radix Root Crops. Let's build up a picture of how oca behaves in a range of locations.

Friday The 13th - Yet Another Oca Shocker

2010-08-14T20:24:00.000+01:00

Roamin in the gloamin at Oca Acres yesterday, I noticed that one of my seed catching envelopes was hanging in a somewhat forlorn manner. Closer inspection revealed the reason - the pedicel bearing the pod had shrivelled and turned black, leaving the envelope dangling like a limp wrist. In the strong breeze, it looked precariously close to detachment. As the damn thing had obviously failed in its job, I removed it. I could see, snug at the bottom, a shrivelled pod, just like the unfertilised ones that seem to have been dropping off the plants in depressing quantities. I was all set to consign the whole kit and caboodle to the compost heap when the dying rays of the sun revealed more: some freshly-minted oca seeds, backlit by the yellow light. 091710 has produced the first seeds of the season. May the season be long and the harvest bountiful.

Potatoes - We've Ingested the Infested

2010-08-13T06:46:00.004+01:00

While other parts of the country are, apparently, dry and droughty, the same cannot be said of Cornwall. The predictable result is that, as I mentioned earlier, blight has destroyed our potato crop. Still, it does present us with the opportunity to try a few of the eclectic mix of varieties that happen to have ended up growing here, albeit a little earlier than anticipated. For the purposes of the taste test, they were boiled, with a little sprig of mint. Here goes:

From top, clockwise: Gloucester Black Kidney; Vales Emerald; Rote Emma; Purple Peruvian; Nicola; Robinta

Gloucester Black Kidney: a good tasting, dry and floury variety. Lovely appearance with distinctive kidney shaped tubers - well named. White flesh despite the purple skin. Excellent except for the pitiful yield. From Nip it in the Bud

Vales Emerald: huge tubers and lots of them. Firmer than the above, probably a good baker. Flavour initially unremarkable, then left a bitter aftertaste and a harsh sensation in the back of the throat. Nice yield, shame about the taste. From Nip it in the Bud

Rote Emma: smooth, waxy, very pleasant. Pink flesh. Good yield, but wins the Mollusc Medal for its enduring appeal to slugs. We like this one too, but somehow the slugs always get there first. Originally from Ulrike Paradine

Purple Peruvian: dry, floury, slightly "nutty" taste. Delicious, purple fleshed. Firm, doesn't break up easily, a good all-rounder. Just the thing before or after manual labour at 0-4000m. Brilliantly camouflaged in the soil - we always miss loads. Horribly susceptible to blight and although they crop reasonably, tuber size is not impressive. Despite this, we have been growing them from our own seed for over ten years now. Purple mash will create a stir at the most staid dinner party.

Nicola: waxy, with a good flavour. Good yield, worth growing again. From Nip it in the Bud

Robinta: waxy/ buttery flavour. Very pleasant, would make an excellent salad potato. Good yield. Will be growing it again. From Nip it in the Bud

Some old Greek guy once mentioned that one could never step in the same river twice; so it is with the evolution of pests and pathogens. As tasty as Gloucester Black Kidney and Purple Peruvian have proved themselves to be, they are, in this area at least, no longer practical for fungicide-free horticulture. These worthy stalwarts from days of yore just don't cut the mustard when it comes to withstanding the virulence of Blue 13 and its successors. Were Heraclitus around today, he would perhaps concur: time to move on.

Like the light from a distant constellation that's dying in the corner of the sky, these varieties are the product of another age, now past. In the song by Paul Simon, from which those lyrics are lifted, he exhorts: don't cry, baby, don't cry. He may have a point: it's perfectly possible, in these days of miracle and wonder, to envisage an elusive affiliation of potatoheads and tomatoheads, breeding new, tasty, blight-beating varieties; they could transfer genes from these oldies to blight resistant ones, thus combining the best of the old with the best of the new. They may be old, but they ain't necessarily cold. The heirloom potatoes, I mean. Let's hear it for cross-pollination - a bit of sexual healing may yet knock Phytophthora infestans off its perch. So join, why don't you, some of the people already engaged in this work: Rebsie Fairholm; Frank van Keirsbilck; Vegetable Heaven; Tom Wagner; Patrick Wiebe; Open Plant Breeding Foundation. You have nothing to lose but your free time.

Podzaformin

2010-08-02T07:30:00.009+01:00

Yes, it's that time of year again in Cornwall when the holiday hordes descend and formerly deserted beaches are suddenly packed with neoprene clad dandies jockeying for position on the surf. More importantly, it's the season when the oca seed pods start to form. Actually, they seem to be appearing a little earlier on this year's seedlings than on their parents, who were, of course, born and raised in 2009. The optimist in me thinks this is due to rapid adaptation to our climate and daylength regimes; my inner sceptical rationalist would prefer to withhold judgement and gather additional data for a few more years.

Here are the first ones I've noticed this year, on 091710, a seedling from 0917, which last year was among the first to set seeds. Pure coincidence? Perhaps, but I'm not taking any chances and will be enveloping the pods and their precious cargo as per 2009. To paraphrase a song from Monty Python's Meaning of Life (but only just) - every seed is sacred, every seed is good, every seed is needed, in your neighbourhood.

In my neighbourhood, I keep noticing additional small oca seedlings peeping out from the skirts of my chillies. So far my attempts at disentangling their root systems from the overbearing chillies has proved successful; I've planted them in any available space in the hope of getting a few tubers by the autumn. It may be a bit late now for some of these tiddlers, but I'm keen to give them a chance, just in case one of these slowcoaches contains the elusive genes for daylength neutrality. Once they're past the small and delicate stage and their stems start to lengthen, they can make quite rapid progress.

I'm still pondering on the exact structure of some of the flowers I've seen. More on the myriad morphs of Oxalis tuberosa when I can get out on a sunny day, examine the flowers properly and hopefully get some shots of their generative gubbins in all their confusing glory.

Getting High with Sweetpotato Seeds

2010-07-29T07:06:00.000+01:00

Now here's something you don't see very often - sweetpotato seeds. Not for illicit ignition and inhalation as was reportedly the fate of other morning glory seeds when I was at school. And not just any sweetpotato seeds, mind you. These are from Papua New Guinea. From the Eastern Highlands region, where they grow in diverse profusion despite the cool climate. Exciting - especially when you read the accompanying note about growing conditions: "long misty mornings and cold nights". That sounds about right.

There is the promise of more seeds at some stage. Excellent. One thing you can be sure of - I won't be smoking any of them, they're far too precious.

Imagine my surprise when they turned up, all unexpected. Last year, at about this time (which is close to my birthday), I issued the Universe a challenge - provide me with the seeds of high altitude New Guinea sweetpotatoes, among several other things. Well, it would be churlish to complain about the speed of the service and the fact that a few items on that list are still outstanding. But I've always been a bit churlish, so thanks, Universe, but what about some Ipomoea minuta, Apios fortunei and true ulluco seed of the day-neutral persuasion?

Blight is Busting Out All Over

2010-07-22T15:46:00.002+01:00

The recent prolonged spell of wet weather has meant that potato blight has devastated our potatoes and outdoor tomatoes. Again. It's singularly dispiriting to look at the mark of the beast all over that formerly healthy foliage and it's hard not to feel that some sort of divine retribution is involved. Since this picture was taken, things have got a whole lot worse. I could wax lyrical about suppurating sores, expanding lesions and stem collapse, but I'll spare you the gory details.

Cornwall does seem to be an evolving centre for Phytophthora diversity - I suppose our moist, mild and humid climate is responsible for that. Potato blight (Phytophthora infestans) has been around for a long time, although it has recently undergone rapid evolution due to the rampant coupling of the original A1 strain with A2, which arrived in 1978. This unholy union produces oodles of oospores, the tough walled, overwintering products of sexual reproduction. These germinate to give all sorts of charming new variants, ready to attack previously "blight resistant" varieties. I'm hoping that Tom Wagner and his worldwide web of collaborators will be able to develop some new varieties of both potatoes and tomatoes to deal with this challenge.

We also have Phytophthora ramorum, the ominously-named Sudden Oak Death, which, ironically, has mainly been killing rhododendrons. Lately it has jumped hosts and is now attacking Japanese larch (Larix kaempferi), an important forestry tree hereabouts. On a recent train ride along the edge of Bodmin Moor, I could easily see the damage - trees with brown crowns, releasing millions of highly infective spores. Some 250 hectares of Japanese larch are due to be felled in this region, in an attempt to contain the spread of the disease. If it's anything like potato blight, I expect that it's already too late. And let's not forget - we have our very own Cornish Phytophthora - P. kernoviae, first described from the Truro area in 2003. Its favorite host is, at present, the rhododendron, which is plentiful, in both the wild form (Rhododendron ponticum) and numerous ornamental varieties. It also likes beech and magnolias. Owners of historic Cornish gardens must be quaking in their boots.

The Peruvian Purple potatoes were the first to go - we'll lift them a bit later. I was more interested in trying Rote Emma. This is a pink-skinned, pink fleshed variety that was given to me by Ulrike Paradine. I know very little about it, other than it tastes delicious. Unfortunately the slugs seem to agree, so an early harvest might not be such a bad thing. Thanks, Phytophthora.

Here are some Rote Emmas fresh out of the ground. Blight-blasted foliage removed for the sake of propriety.

Here they are after a bit of a wash, with a cut tuber to show the flesh colour. I expect they're full of healthy antioxidants.

And last but not least, boiled, with a pat of artery-clogging Cornish butter. Comfort eating at a time of crisis.

Mecha-mecks are Doing Swell

2010-07-16T07:00:00.000+01:00

I wouldn't go quite that far, but swelling is what they're doing, as this shot shows. Top growth has been disappointingly minimal, but it seems like they are concentrating their energies into developing their storage roots; these appear to be a combination of swollen hypocotyls as well as roots proper. Perhaps due to the limited rooting space, they're now pushing up, rather than down. I suppose this should be my cue that it's time to pot them on. I've avoided this so far, partially through laziness, but also because I've read that they resent root disturbance.

I was hoping for bindweed type growth to issue forth from the top of the plants like Silly String and wrap itself around any available object; what I've got so far is shown to the left. It could be, as I suspected, that it's not really warm enough here for that kind of exuberance. Or, another possibility - they're storing up energy for a more impressive performance next year. One can live in hope. In either case, it doesn't seem polite at this stage to take a bite out of any of them - not just yet. I am tempted, though. In the name of scientific enquiry, you understand.

July Is Busting Out All Over

2010-07-12T09:35:00.009+01:00

Starting to, anyway. By which I mean that the first oca flowers of the season are here - on 09081, one of the seedlings I raised from from plant 0908. It does sometimes feel like a bit of a merry-go-round, hence my scrap-salvage adaptation of the old song title from Carousel, a musical whose plot still perplexes me. I'm dizzied by trying to manage the ever-expanding oca brood and everything else that life demands. Or, switch that rotating axis from vertical to horizontal and you have another take on it - an oca treadmill. Enough free association already - let's get back to the matter in hand.

The parent 0908 produced a good yield of tubers (about 240 grams after frost wastage, according to my records and the tubers were a reasonable size). It was a big and vigorous plant, with a short styled flower.

Looking at the flower of 09081 more closely, I do feel a little confused; it doesn't seem to conform to the three morph theory of oca flowers. The anthers and styles appear to be clustered together, more or less, at the top, without the usual segregation into distinct whorls. So has oca pulled a flanker yet again, after my strenuous efforts to understand floral inheritance in this wild child of the Andes? According to my CIP descriptors and the handy illustration contained therein, it most resembles number 4, the semi-homostylous form, a slight variation on the theme of the bog standard mid-styled morph. At least I think it does.

09081 has inherited neither the same floral morph, nor the same axillary markings as its parent - below, on the left is 0908, with 09081 on the right. I wonder what other characteristics have/haven't been inherited by the daughter plant?

There are others not far behind in this floral dance. It will soon be time to get out there and assist in pollination duties. Here's a view along the bed. There are considerable differences in both vigour and habit of growth between individuals, which although not obvious in this shot, can be seen as you walk along the rows.

And here's a sneak preview of within-plot diversity, including some self-sown Amphicarpaea bracteata plants twining around the bamboo canes. Differences between the ocas can be seen quite clearly.

The mild and humid weather has encouraged the growth of many plants, but, right on cue, blight has appeared on the purple potatoes. Drat, drat and double drat. Don't think I can realistically hope for any outdoor tomatoes this year.

No blight on the ocas, but I did find this fella munching through one of the oca seedlings. Most likely it's the caterpillar of an angle shades moth, Plogophora meticulosa, a generalist feeder found on a wide range of host plants. I'd prefer it to indulge its catholic tastes elsewhere and leave my ocas alone. Result? A maiden flight before metamorphosis into a nearby patch of mixed vegetation.

Another Oca Shocker

2010-07-01T15:10:00.005+01:00

"Lucky" is not alone. I was weeding by the edge of a bed yesterday, when I noticed some more oca seedlings. Several more. So it seems that oca seeds can overwinter, then germinate and develop quite well here. I find this revelation rather comforting, as it suggests that it might be possible to sow seeds directly outside (I'm thinking by the thousand) and select for early germination and tough, fast growth.

I have to admit that all these seedlings look healthier than my own ones did at a similar age. I'm guessing that they won't make anywhere near as much growth as their cosseted counterparts before winter, however. Maybe that doesn't matter. It may still be possible to select outstanding individuals from the mob. Alternatively, it might be possible to use some sort of cloche system to warm the soil and get them started earlier, then remove it before they get spindly (as all my indoor seedlings did). I could try it next year.

These country cousins seem to have cobby conformation and a sanguine outlook on life. I kind of like the idea of a self-sowing Inca root crop that inveigles its way into your existing crops. Presumably new oca varieties appear this way in their Andean highland home. You've heard of TPS (True Potato Seed - if not - look here). May I introduce the latest in oca acclimatization technology - TOS - True Oca Seed. Once I've figured out how to get large crops of seeds on a regular basis, I'll be looking for a bunch of fellow TOSsers to help grow and select them. RSVP.

Great Ocaspectations (2) Oca Genetics: This Much I know

2010-06-25T22:37:00.007+01:00

OK - it's time to disperse the cloud of unknowing that obscures the summit of Mt Oca.

I'm going back to basics, just like former Prime Minister John Major did; I hope it works out better for me than it did for him. I make no apologies for using the technical terms for various processes - if I've got to learn them, so have you. "This Much I Know" could be rephrased more truthfully as "My Brain Hurts".

Brace yourselves.

Oca's genetic code is located on eight different chromosomes. In a "normal" diploid species they occur as pairs, which means 2 x 8 =16 chromosomes in total, see below:

In oca's case, however, the picture is more complicated: it is is a polyploid, with four sets of each chromosome pair, (2n =8x = 64). This means it is an ocatoploid, sorry, octoploid, with 64 chromosomes in total:

It is also an alloploid, formed when the different genomes of precursor species joined together. The latest evidence suggests that it may be an auto-alloploid. Resist the lure of a darkened room and bear with me for an explanation: this is gonna hurt me more than it hurts you.

What apparently happened is that one diploid parental species with the diploid chromosomal complement AA, doubled its chromosomes to form an autotetraploid AAAA (2n= 4x = 32, no chromosomes from any other species):

This then combined with two separate diploid species (BB and CC) or one allotetraploid (BBCC), itself formed by the uniting of two diploid species and nothing to do with the BBC, except perhaps in that they both contain a lot of repeats.

The result is AAAABBCC, the auto-alloploid Oxalis tuberosa we all know and love, with half the genome coming from species A, the other half from the B and C genomes, one quarter each.

The identity of these species is still not entirely clear, although likely suspects are Oxalis chicligastensis from northwestern Argentina and Bol/WT, an as-yet-unnamed Oxalis species from Bolivia.

Much of this information comes courtesy of Our Lady of the Ocas, Dr Eve Emshwiller, whose pioneering work on the genetics of Oxalis tuberosa is starting to unravel the mysteries of this crop. Her latest paper from 2009 gives much more detail on this and also has a lovely picture of a collection of oca tubers that are positively indecent in their diversity. Food porn I've heard of, but tuber porn (which this surely is), is a new and welcome addition to my life. Not such an inappropriate connection as it happens: oca has strong sexual associations in Quechua language and culture. The phrase oqa-tarpu, for instance, which literally means "planting ocas", doubles as a term for sexual intercourse. Another useful piece of information is that an oqaratu is a stupid, lazy or vacillating person. Feel free to spice up your domestic disputes about the gone-off milk, the missing car keys or the unpaid bills with this useful term of abuse.

In terms of character inheritance and plant breeding, where does this leave us? We know that oca is an obligate outcrosser (allogamous) with a system of self incompatibility based around three stylar morphs, short medium and long (tristyly). The genetics of this have been elucidated here. Basically, the inheritance of flower morphs was shown to be tetrasomic (involving four versions of the same chromosome at meiosis) and diallelic with two alleles of each of two genes: S,s and M,m, with S preventing the expression of the M gene - a process known as epsistasis. Various combinations of the above M and S genes and their alleles give rise to the three flower morphs. And it's all happening on the autotetraploid subsection of the genome.

Don't confuse epistasis with dominance. Dominance is caused by the dominant allele of a gene overriding a recessive one. Epistasis involves separate genes in which one has a cancelling effect "upstream" of the others - like trying to change channels on the telly when it isn't plugged in yet. Or (how's this for topicality?) head straight to Daughter of the Soil's post here for a practical demonstration.

So if all the flower morph activity (a big if) is located on the autotetraploid AAAA chromosome chunk, there must be a whole lot more going on over at the BBCC section of the genome. There will be plenty of genes located in these other ancestral genomes which may not be inherited tetrasomically. Which genes are where and which ones are inherited in which way are as yet, to me anyway, completely and utterly unclear. I feel the mists descending and the summit of Mt Oca disappearing from view. That or a migraine coming on.

It's probably a safe bet however, that oca is heterozygous for many traits and that these will segregate in subsequent generations in all sorts of complicated ways due to its mixed up genome. Oh joy. Mendel was lucky he chose peas. Nevertheless, I would imagine that the traits will fall into two categories, qualitative and quantitative.

Qualitative traits are those likely to be under the control of single genes or at least only a few genes: a binary on/off, present/absent, as shown in classic Mendelian inheritance (see Daughter of The Soil's blog for a thorough and lucid exposition of all of this).

Quantitative traits are ones which grade seamlessly from one to another along a continuum. They are under polygenic control, that's to say many genes, perhaps on different chromosomes, have an influence on any particular characteristic. These include, in some other tuber crops at least, traits such as yield, tuber shape and flesh quality.

I suspect, although I don't know, that tuber colour and plant form in general are maternally inherited - I should be able to put this to the test when I harvest the tubers in the autumn. Among the more obvious traits I can detect above ground are stem colour (red/green) underside of leaf (purplish/green):

And the absence or presence of axillary colouration. It would be fun to try and work out the mechanism of inheritance in these cases. If only I knew who their parents were.

Under the circumstances of my overwhelming ignorance, it is probably as well to follow the time-honoured route used by some potato and sweetpotato breeders - recurrent mass selection. It's a case of crossing varieties in every possible combination, then sowing and selecting their progeny, eliminating the feeble or substandard and keeping the best for the next breeding cycle. I could also do a little controlled crossing here and there and see what happens.

My main concern is that my seedlings have been derived from a handful of varieties, possibly less. Ideally you would start with a population of at least twenty unrelated individuals in the "crossing block". All is not lost however, as it should be possible to incorporate genes from new varieties by crossing them with the other ones to introduce more genetic variability - a process known as introgression.

There you go - that's close to the sum total of my knowledge of oca genetics at present: not a lot. That darkened room awaits me. What about you?

A Surprise Ocaurrence - What's That Lurking in My Lathyrus?

2010-06-19T22:34:00.000+01:00

Passing one of my caremyle pots the other day, I did a sudden double take. There, nestled beneath the foliage, were two little seedlings, with trifoliate leaves.

Intrigued, I looked closer. Not clover, nor Oxalis corniculata, but little oca plants - definitely. Unlike Queen Victoria, I was amused.

I must have repotted the caremyle with some spent compost containing oca seeds, which had then decided to germinate. I quickly extricated them and planted them in modules; I'll reunite these foundlings with their extended family in the oca plot when they reach the age of majority. Scrutinising the surface of the pot more closely , I noticed further seedlings starting to show.

Not long afterwards I was hoeing off some weeds and oca volunteers which I wanted to remove from a bed. I noticed that one of the ocas, small and stocky and moments before a picture of health, actually had cotyledons. This was none other than my first oca seedling to appear spontaneously outside in one of our beds and I had, in my enthusiastic ignorance, decapitated it. I held the the bisected beauty in my hands with an expression of mute incomprehension. No I didn't - I swore with undignified intensity and rapidity. Regaining my composure quickly (all of 30 minutes), I replanted the rootless stem and I'm hoping that I can persuade it to re-root. It at least proves that oca seeds can germinate and develop outside satisfactorily, although how large a plant it would have made before the winter is anyone's guess, especially with me acting plum loco parentis. If it survives, I'll name it Lucky, after that darn dog from that ol' poster:

Great Ocaspectations (1) Overdosing on Oca

2010-06-11T07:30:00.008+01:00

Here's a view of my oca seedling bed as it looked a couple of weeks ago. Each pot contains a single seedling raised by yours truly this year, from the seeds I harvested last autumn. It may or may not be an idle boast, but I reckon that I've now got the largest collection of oca germplasm in the whole county of Cornwall. It all looks uncharacteristically neat and tidy, which rather belies the frenetic panic with which they were planted a few weeks ago.

Some friends had invited us over for tea in their lovely moorland garden. It was a glorious afternoon, with the hot and penetrating sunshine moderated by a pleasant breeze and an almost alpine aspect. I was aware that afternoon was passing into evening, but the sandwiches, cakes, drinks and good conversation made the thought of lifting my corporeal bulk from the lounger even more unappealing. The sun's rays were weakening - and so was my enthusiasm for oca planting exploits. Oh well, tomorrow perhaps? I was gently but firmly reminded of my promise to get the job done. Suitably chastened, I hurried home to collect seedlings, pots and other equipment and get to work.

Working feverishly to plant and label them all before the remaining light faded, I was reminded of Kirosawa's film Dersu Uzala. In one memorable scene, the Nanai hunter saves the life of the Russian army officer Arsenyev by rapidly building a reed hut to protect them when they are caught out by an unexpected twilight blizzard. If I'd stopped daydreaming and searching for poetic comparisons, I might have got it finished a bit sooner. Thanks to the diminishing light levels I can be fairly certain that my attempts to distribute the seedlings randomly have been successful - if more by accident than design.

By my calculation there were approximately 80 oca seedlings to be housed - the products of semi-controlled crosses - that's to say I knew who their mothers were, even if their dads were strangers to me. I attempted to grow ten seedlings or more of each variety, but some failed to come up or were scythed from below by damping off fungi. That's life. Each seedling from a known mother bears her appellation, RX0909 for instance and then an additional number to distinguish the siblings from one another - 1,2,3 etc.

Ah, but I'd reckoned without another 40 seedlings whose parentage was entirely unknown and I had sown during a what-the-hell moment back in the early spring. Suddenly there they were, pleading with me for a stay of execution - till the autumn at least. There was only one thing for it - I'd have to fit them in somewhere, somehow. No wonder I was working at such a breakneck pace. These seedlings I gave designation RX1001 , 02 and so on. I planted them nearby, turfing out, literally, some other less worthy candidates, a bunch of chillies. What is abundantly clear is that this relationship is entirely one-sided - I am at the beck and call of the ocas. I am their dutiful slave. They've domesticated me.

The canes are there to help prevent the plants from sprawling over and through one another and will also allow me to access the flowers and pods more easily - I hope. The pots will, as they did last year, keep the tubers of each variety separate. Under ideal circumstances I would have been able to give each seedling plentiful root run and space from its neighbours and planted them directly in the ground. Unfortunately, that luxury seems to have eluded me yet again. Anyone who has tried determining the provenance of stray oca tubers scattered through a Somme-like plot will know why I have opted for this horticultural apartheid. I have earthed up the stems once so far and will do so again, in the hope that this will encourage the development of tuber-bearing stolons, just like with potatoes. The bare soil, by the way, will be mulched in due course.

What with these seedlings, the tubers from last year 's seedlings, the wrinkled old retainers and new arrivals courtesy of Frank van Keirsbilck, I must have planted around 140 genetically unique individuals this season. Frank managed to get good germination from the seeds produced by my plants of "Pink Dragon", the variety he raised a couple of years ago. So that adds another 90 or so individuals to this newly evolving secondary centre of oca diversity in NW Europe. I hope we're getting up to the kind of numbers where we might start to see some interesting new traits appearing. We're also reaching the point at which some serious winnowing of duds needs to occur.

But before I get too trigger happy, it is probably as well to pause and consider what combinations of which traits might actually be desirable in those oca seedlings that escape the indignity of being untimely ripped from their pots. Here goes:

1) Early tuber formation during long days/ high yield (large tubers)

2) Profuse and early flowering

3) Vigorous and disease resistant

4) Good tuber quality and flavour

1) The main obstacle to oca's adoption as a food crop at our latitudes is its inability to form tubers during the long days of summer. A handful of marbles harvested in October can only lead to unfavourable comparisons with the potato and contribute to oca's notoriety as an "experimental crop". No, this just won't do: I'm looking for day neutral forms, or ones that can tuberise when days are significantly longer than 12 hours. I won't rest until I find one, preferably several. Perhaps I ought to set a harvest date some weeks before the end of September, lift the plants and keep those bearing the largest tubers.

2) At this stage in the game it is vital to obtain precociously floriferous plants with the ability to set a plentiful crop of pods. Seeds contain novel and unique combinations of genetic material and are the raw material upon which selection, natural or otherwise, works. Can't have too many seeds.

3) Vigour and disease resistance are also very important. Differences in vigour start to show early on in a seedling's life. I suspect vigour could be linked to early flowering and - maybe - early tuber formation. If some seedlings are small and puny and prone to damping off, chances are their offspring will inherit this weakness. I'll weed them out, so that their contribution to the next generation is nil. I'll be watching disease and pest susceptibility too.

4) At the moment my main concern is to get plants that reproduce efficiently, both sexually and vegetatively. That said, I ought to check that the tubers resulting from my mini breeding programme are of acceptable quality and are not too bitter, fibrous or unpleasant in any other way.

In my next post I will discuss what little I know about oca genetics and how I might use this knowledge in my breeding programme.

It's a Seed, But Not As We Know It, Jim

2010-06-05T23:15:00.002+01:00

Actually Jim, it's an anthocarp, a mauka anthocarp. On one of my mauka roja plants. I'll put the tricorder down for a minute and explain. An anthocarp is a specialised fruit found in the family Nyctaginaceae to which mauka (Mirabilis expansa) belongs. And before you ask, yes, I do know what a nail brush is.

Seems like my clumsy fumblings have resulted in a single, successful pollination. Alternatively, it may have happened spontaneously, without any connection to the prodding and poking which I doled out to all the hapless flowers I encountered.

What looked like pink petals in my previous picture weren't - they were colourful sepals standing in for the petals, which went AWOL sometime in the evolutionary history of this family. Similarly, what looks like a ripening seed is, from the botanist/pedant's viewpoint, a fruit, albeit somewhat unlike the common conception of one. It's an achene (dry fruit) wrapped in a persistent calyx - known in botanical shorthand as an anthocarp. In mauka's case this outer wrapping is covered in sticky hairs. These must help the ripe seeds stick to any passing birds or animals which then distribute them to new areas.

Here's a close-up of the achene, divested of its glandular, sticky coat. There are definite ridges present on its surface - a common feature in Mirabilis species.

So, although I don't know whether this mauka propagule is viable, it seems likely that, under some circumstances at least, mauka can self pollinate. This can only be a good thing.

Oh Heck, Here's Mecha-meck

2010-05-24T13:30:00.022+01:00

In my quest to create the perfect sweetpotato for our unsympathetic climate, I've been doing a bit of hunting around for some of its wild relatives. This is an approach used by proper plant breeders to introduce genes for disease resistance and adaptability into major crops. I'm not sure whether this means that I'm now dragging myself up to their level, or whether the plant breeding brethren (and sistren) will be tainted by association with my madcap antics. If you don't tell, I won't either.

Mecha-meck or bigroot morning glory (Ipomoea pandurata) is one of the most cold tolerant sweetpotato relatives, being found in parts of the Eastern USA and Canada which have much colder winters than we do here in the UK. Its roots are edible and taste, unsurprisingly, like a sweetpotato, although several references mention that they are often somewhat bitter. Although said roots can survive sub-zero temperatures with ease, it doesn't mean that the vines that issue from them are going to like our cloudy, cool summers. It's what I call the Maypop Paradox, after the "hardy" passionflower Passiflora incarnata. It comes from the same neck of the woods as mecha-meck and although it can easily survive our laughably mild winters in a dormant state, our summers (or lack thereof) are fatal to it. At least whenever I try and grow it. I'm reminded of Mark Twain's supposed quip about the coldest winter he ever spent being a summer in San Francisco. He should have visited Cornwall. Anyway, my guess is that mecha-meck is cast in the same mould and at best its vigour will be severely checked by that lack of summer warmth. Time will tell.

It does, however, have a close relative, Ipomoea leptophylla, which grows out in the western USA at quite high altitudes, up to 2000 metres or so in Colorado, for instance. It has been described variously as delicious, or as a famine food - take your pick. One of I. leptophylla's vernacular names is "manroot" - I suggest caution when Googling that name and make no claims expressed or implied as to what sort of images or text may storm your computer as a result.

Rather than a vine, I. leptophylla is distinctly bushy, which might make it easier to manage as a garden plant. It might take cooler summer temperatures in its stride. That set me thinking about how it might be fun to have a go at crossing the two species and seeing what comes out. That's a lot of mights for one paragraph, but three mights don't make me wrong do they?

These are the seeds of mecha-meck, looking like shaggy understudies for Cousin Itt from The Addams Family. I'm not sure what the purpose of the coiffure is - the seeds are about 1cm long - quite substantial - and I can't imagine that even this amount of fluff would carry them very far on the breeze.

Here are some mecha-meck seedlings with the distinctive delta wing cotyledons which all the Ipomoea species I've ever grown seem to display.

Sweetpotato is a hexaploid with six sets of each chromosome (2n = 6x = 90) whereas mecha-meck and manroot are both diploid (2n = 30); most of the literature suggests that interspecies crosses between sweetpotato and its wild relatives are hard to achieve anyway - never mind the differences in ploidy - which isn't really what I wanted to hear. However, last year's impossibility is this year's commonplace: I recently came across a paper by some Chinese researchers where they had managed to do exactly this. The abstract is here. The actual paper lurks behind a paywall, thumbing its nose, no doubt, at us mere mortals who don't fancy spending $34 on the full text.

This idea of using I. pandurata to increase the cold hardiness of sweetpotato is nothing new - I'm merely ram-raiding the vaults of yesteryear and grabbing whatever takes my fancy. In a 1935 paper in the Journal of Heredity, M G Tioutine outlines his work on breeding sweetpotatoes in the USSR and goes on to describe his attempts at crossing I. batatas with I. pandurata. A few pods were formed, but there's no mention of whether they contained viable seeds or not. I haven't found any other papers referring to his further research on this front either. Judging by the fate of Vavilov, working as a plant breeder and geneticist at this time was not, perhaps, the safest career path in Soviet science. (There's more on Vavilov at Vaviblog - a great, great man).

Tovarishch Tioutine does, however, describe the roots of I. pandurata as tasting similar to Jerusalem artichokes, which doesn't sound so bad after all. Perhaps it's just a case of harvesting them young, before they become tainted with whatever it is that makes them bitter.

So all I need to do now is get hold of some I. leptophylla seeds, grow the plants to maturity, then set up an Ipomoea menage a trois with I. pandurata and the best adapted I. batatas varieties, including ones from the highest sweepotato plots in the Highlands of Papua New Guinea.

Should be an absolute breeze. In the meantime, I'm waiting on the universe to deliver me seeds of yet another Ipomoea: the fabled sweet-tasting, high altitude Andean species I. minuta. I'll throw that into the mix when it finally arrives. I don't know what the collective noun for a disparate bunch of ipomoeas is - could it be an entanglement? What I do know is that I'd like the chromosomes of this motley crew of morning glories to commingle and maybe create something interesting in subsequent generations. You say potato, but I say batatas - and I won't call the whole thing off.

Yabadabadoo - Yabumame's Poking Through!

2010-05-19T08:00:00.001+01:00

This is the emerging shoot of yabumame (Amhicarpaea edgeworthii), whose Japanese name translates as something like bush soy. The more typical trifoliate leaves will follow shortly. It looks very similar to Amphicarpaea bracteata, talet or hog peanut, about which I have been known to hold forth for hours on end to interested parties. They were the ones who didn't nod off, or stare out the window at some particularly fascinating cloud formations. But seriously, just like talet, this is a tasty plant, with the same sort of potential.

It is sometimes classified as Amphicarapa bracteata subsp. edgeworthii var japonica, which suggests that the resemblance to talet is more than superficial. Unlike its New World cousin, it has been subjected to some scrutiny as a potential food crop by the Japanese. If you fancy practicing your hiragana, katakana and kanji comprehension, then here's a good place to start. I tend to skip over the text and look at the pretty pictures. Nevertheless, it's probably a safe bet that these research findings would be applicable to talet as well. Scroll to the bottom for the English abstract. For other hard core Amphicarpaea edgeworthii fans there's more where that one came from. Or maybe I'm the only one.

One of the advantages of the amphicarpic habit is that the plant produces two types of seeds, the cleistogamous, self pollinated ones (underground and overground, just like the Wombles) and the open pollinated chasmogamous seeds from the flowers at the top of the plant. It should be possible to allow or assist the plants in crossing using the chasmogamous route, then sow the resulting seeds and maintain any favourable ones via the seeds produced by the handily self-fertilising cleistogamous flowers. That's my theoretical take on it anyway, which I've had no opportunity to verify or disprove so far.

I'm also wondering whether the two species can be crossed to introduce a bit of extra genetic variation. I haven't tried it and don't know whether it's possible, but seeing as the two are so closely related, it must be an avenue worth exploring.

As to differences, well, A. bracteata and A. edgeworthii are known to be colonised by different varieties of rhizobial bacteria, with A. edgeworthii unable to use the strains found on A. bracteata; A. bracteata, however, can use A. edgeworthii's bacteria. I shall have to see whether any nodules form on my yabumame's roots later on. Not much point having a plant with the ability to fix nitrogen without providing it with the means to do so.

Then there's A. africana - yes, an African hog peanut about which I know precious little, other than that it grows in montane Africa at elevations of around 2000 metres or so. For the sake of completeness, I really ought to try and grow it.

Delving deep into the Gormenghastian recesses of the internet in search of all this stuff is fun, but can't quite compete with the pleasure of devouring a plate of cooked talets, steaming majestically and crowned with a knob of butter. The former I can do any day; the latter, regrettably, will have to wait until the autumn.

Yond Yacons Have a Lean and Hungry Look

2010-05-13T23:25:00.003+01:00

Shakespeare, with his impressive knowledge of plants and their uses, might have looked on my yacon seedlings and said the above. I'm guessing that yacon hadn't made it to London by the 1590s or Stratford's finest scribbler would have mentioned it: "Why man, it doth bestride the narrow border like a colossus and we petty men walk under its huge branches and peep about.... Let me have about me roots that are fat". You get the drift.

Fast forward a few centuries, stepping nimbly from doublet and hose into a zoot suit and let the good times roll with Louis Jordan. "Long, lean and lanky, ain't had nothing to eat" is his description of the eponymous protagonist in the 1945 hit Caldonia. That would apply equally well to my yacons. I've been waiting for the weather to warm up and lacking the necessary space to pot them on, they've got distinctly malnourished. Ain't that the truth! Well Louis, they're my babies and I love 'em just the same. I'm hoping that as soon as they get into the ground, they'll forgive me.

Getting Arty and Chic with Helianthus

2010-05-05T21:43:00.046+01:00

Here's a brand new way to eat your Jerusalem artichokes: blanched - the shoots, that is. I call them artichicons. If it works for rhubarb, sea kale, chicory and a host of other plants, why not that irrepressible artichoke impostor Helianthus tuberosus? Lest you think me smug, I had absolutely no intention of doing any of this. Call it serendipity, call it fortuitous, but as far as I'm concerned, it was an accident.

An errant patch of rampant Jerusalem artichokes needed eliminating. I couldn't face digging them up, so the answer seemed simple: I'd cover them with light-excluding weed control fabric and hope the buggers died off before the bed was needed. I'd reckoned without girasole mio's thrusting and aggressive growth, however.

Weeks passed, then the fabric began to rise like a bloated loaf. Intrigued by this Greater Black-Backed Multiple Tumescence, I pulled the cover away to reveal a forest of pallid artichoke shoots. I picked one and chewed on it for a moment. Not bad, I thought. Not bad at all. I harvested the rest and later that day, I cooked them.

Although ginger, garlic, soy sauce and chillies can make most things palatable, these artichicons really were rather tasty. No doubt correct varietal selection and time of harvesting would lead to an even better experience, reducing the chew factor, but for a first (and unexpected) attempt, I was quite pleasantly surprised. More research is therefore needed, but all in all, a topping way to eat your topinambours. No more will I look upon redundant artichoke capacity with a sinking heart - I'll fire up the wok instead.

Can I Mess With Some Camas?

2010-04-30T07:07:00.005+01:00

Cruising idly down the aisles of a local garden centre, my eye was suddenly drawn to the remaindered bulbs. I always feel sorry for these poor shrivelled critters, randomly scattered in sawdust-lined open coffins, in a state of incipient mummification. Sometimes I take pity on a few and buy them.

On this occasion some forlorn camas bulbs impinged on my consciousness. Oooh. The bulbs of Camassia species were an important food source for native Americans in western North America and are also eaten by bears, gophers and deer. I've been meaning to grow them for years, but somehow have never got round to it. Tell a lie, I have grown them before, but when it came to harvesting and eating them, I flunked.

There I stood, presented with the opportunity to purchase two of the most important culinary species, C. quamash and C. leichtlinii. I knew I had more than enough on my plate, I knew I shouldn't, but my heart went out to these benighted bulbs (plus I was more than a little curious to grow and taste them).

So I bought a few of them. I suppose I ought to issue a warning about not trying this at home - don't do as I do, do as I say. Camas bulbs are definitely edible, but can be mistaken for death camas (Zigadenus venenosus),which definitely isn't. Luckily, death camas flowers are white and have a different appearance to the true camas. I will be checking the identity of this lot scrupulously before consuming them. I chose two blue flowered varieties to further eliminate the chances of misidentification. On the left are the bulbs of C. leichtlinii; those on the right are C. quamash. Having failed to provide a more accurate means of measurement in my photo, I'm reduced to comparisons with other bulbs: C. leichtlinii are about the size of daffodil bulbs, whereas the C. quamash are similar to onion sets. Yeah, a ruler would have been better.

They are supposedly edible both raw and cooked and like Jerusalem artichokes, their carbohydrate reserves are stored in the form of inulin. I bet this has all sorts of advantages for the health of your gut flora. How long before someone starts marketing them as, for example, "the Wonder Food of Washington State, sustainably harvested" ?

Although these ones were looking a little soft and sorry at the time of planting, I have no doubt that they'll recover and I'll get my chance to try this taste treat in due course.

Those First Nations camas harvesters took considerable pains to keep favoured patches free of extraneous objects and brush, often maintaining the camas meadows by burning. It was gardening in all but name. They lifted the bulb-bearing turf in chunks, removed the biggest bulbs and then replaced it. This kind of disturbance favoured the growth and spread of the bulbs. Once harvested, the bulbs were pit roasted, often for several days, using hot rocks in a deep hole lined with seaweed, fern fronds, tree branches and other plant material. In went the camas bulbs and the pit was sealed with more branches, sand and soil. This slow cooking broke down the inulin into fructose, producing a very sweet mass, supposedly tasting a bit like baked pear. I can't yet validate this claim, but it sounds good.

Camas grows well in this part of the country and there's no reason why some of our otherwise unproductive lawns couldn't support a crop of it; in terms of edible ornamentals it's definitely in the first rank. If a bluebell wood meets with your approval, then a camas meadow like this should be a welcome sight. Photo by Jenny A. Moore.

So, in answer to the question posed in this post's title - I can and I will.

A Precocious Talet

2010-04-26T07:20:00.004+01:00

Here's a shot of my first crop of talets for 2010. This very small and exceedingly early harvest results from the concatenation of events beginning late last year. Frank van Keirsbilck, purveyor of all things seedy and exciting, sent me the underground beans from one of his Amphicarpaea bracteata varieties in November. As I was otherwise detained in hospital, I was unable to rescue the seeds from a warm room and they promptly germinated. By the time I had recovered sufficiently to care about such things, the majority of them had exhausted themselves in their padded envelope prison and rotted. A few however, seemed to be alive, so I potted them up and put them on the windowsill with the maukas I mentioned previously. This was in late January, or maybe early February. They started to make the typical vine-like growth, but then rapidly switched to reproductive mode: the stems stopped elongating and flowers began to appear.

Now the leaves have yellowed and are dropping off, revealing a small crop of blackish pods. Presumably the short daylength was enough to arrest their usual vegetative development and initiate flowering and seed formation. Put it another way - I inadvertently tricked them into flowering at the wrong time of year. If nothing else, it's a fairly graphic illustration of how profound the effects of daylength can be on plant development.

It's also made me think about the kind of characteristics I'd like to see in a domesticated talet plant. For our climate we want a plant that makes rapid growth during the early stages of the growing season and then switches over to intensive reproduction in late summer, laying down large quantities of fat seeds for the winter. Realistically, this will need to begin before the equinox, as temperatures and light levels have often fallen too low for acceptable growth after this time and the spectre of an early killing frost frequently stalks the land.

It is apparently the case that yabumame (Amphicarpaea edgeworthii), talet's Asian cousin, shows variation in time of flowering according to latitude; northern latitude plants begin flowering more quickly after sowing and continue for longer than their soft southern counterparts. It's a fair bet that the same is true in the case of Amphicarpaea bracteata. So the hunt is on for northern provenance seeds. This can mean only one thing - Canada.

One particular place in Canada with a climate at least vaguely reminiscent of ours would be a good place to start: Prince Edward Island. Like Anne of Green Gables, whose resolute optimism saw her through the trials of life, I'm positive that another citizen of Canada's 'Garden of the Gulf ' will be able to supply me with some seeds and maybe throw in a tuber or two of Apios americana for good measure. Step forward please.

Other than that, I'd like to see an Amphicarpaea plant that doesn't aspire to be the kudzu of my vegetable patch. All the plants I've grown send out rangy, tentacular shoots and sparse leaves with long flower stalks in their axils. A similar sort of growth habit is common to many other wild beans and is, no doubt, highly adaptive. While hunting for the scattered beans may be OK for wild food afficionados armed with digging sticks, rush baskets and plenty of time, it does rather hamper the gardener's attempts to harvest meal-worthy quantities. It also contributes to the impression that the plant is more trouble than it's worth and should be evicted at the first opportunity. Exit stage left, pursued by a hog.

Leaf spacing is a function of internode length: shorten the distance between leaves and you get leafier, bushier plants with a more manageable habit of growth. Perhaps these plants would, as a result, focus more effort on producing the bit we want, the beans, rather than those serpentine shoots with the insatiable wanderlust. The result? More beans per square metre. As short internodes are produced by recessive genes in other legumes, I suspect the same is true for Amphicarpaea. I have a nagging suspicion that I could be waiting a while for a homozygous bushy plant to appear. Nevertheless, like Anne of Green Gables, or more particularly, Mr Micawber, I'm confident that eventually something will turn up.

Blooming Marvellous Maukas

2010-04-19T20:23:00.001+01:00

I've been studying, with a degree of anticipation, the development of flower buds on the mauka 'roja' plants which Frank van Keirsbilck gave me last summer. They spent the winter confined to a windowsill in a fairly cool room; a few weeks ago I noticed that some of the stems were elongating into what I optimistically took to be inflorescences. Daylength at the time was probably a bit less than 12 hours, which suggests that mauka requires short days to initiate flowering.

The waiting is now over - a couple of flowers have opened in the last few days. The 'blanca' plants, located in a warmer spot, have grown much bigger and show no signs of flowering. I'm pondering on the significance of this observation.

The flowers are not the most photogenic objects I've ever pointed a lens at, but like those Elizabethan miniatures, they repay closer investigation. I just wish I hadn't mislaid my hand lens when I needed it most; like as not, it is lying buried beneath a pile of festering oca stems and tubers and will resurface via the compost heap at some future date.

I won't be entering this image for the Henri Cartier-Bresson Award, but at least you get an idea of the flower's petite, pink appearance. The anthers have, relatively speaking, whopping great big pollen grains. I tried to shift them onto the stigma, but I fear my clumsy fumblings did more harm than good. The buds themselves are covered with sticky hairs. Imagine my horror when an unopened bud adhered itself to my shirt sleeve, then detached itself from its mother and left this world an uncorrupted virgin. I suppose that's what you could call coming to a sticky end. My clumsy fumblings were certainly counterproductive in this instance.

Mauka's glamour-puss cousin, Mirabilis jalapa, the Marvel of Peru, has big colourful, fragrant flowers, which featured in pioneering studies on Mendelian inheritance of flower colour in the early 1900s. It also took a leading role in the first conclusive case of cytoplasmic inheritance, where genes outside the nucleus were shown to affect the plant's possession (or not) of variegated leaves. The genus Mirabilis as a whole are also known as the four o'clock flowers, this being the time in the afternoon at which they usually open and begin releasing their heady fragrance. The apparent cause is the decline in air temperature as the sun's rays weaken, rather than any direct association with a particular hour of the day.

Mauka, by contrast, seems to be a bit of a shrinking violet, with small flowers and I've yet to catch them in fragrante delicto. On my windowsill, the flowers seem to open at night, followed by closure early the following morning. Could it be that four o'clock actually refers to 4am rather than 4pm? I'm not sure if I can face staying up into the wee hours, headtorch, tweezers and paintbrush in hand in the hope of effecting a successful pollination. I need my beauty sleep.

Many species of Mirabilis are facultative outcrossers, that's to say they prefer to cross-pollinate, but are able to self-fertilise if a better pollen source isn't forthcoming, or if the moths which usually pollinate them are prevented from flying by low temperatures. It will be interesting to see whether this is also true in mauka's case. I'll be looking out for swelling anthocarps, the distinctive dry fruits which are characteristic of the family Nyctaginaceae to which Mirabilis and Bougainvillea belong.

The case for inducing flowering in mauka by daylength manipulation grows ever stronger. Let's hope I'm man enough to remove and replace light excluding covers over a few plants for a few weeks this summer in the hope of tricking them into flowering. Then I can let the moths do the rest.

Up Come the Ocas

2010-04-12T21:15:00.008+01:00

The next generation of ocas are on their way. The seeds I collected last autumn seem to be fairly viable, without recourse to any potassium nitrate or other germination stimulants. I did give them a bit of a clean in a dilute bleach solution though.

From tiny seedlings big tubers grow - that's my earnest hope. This little fella may be one of the gifted and talented who will be fast-tracked to glory in the months to come. Or not.

As I think I may have mentioned previously, breeding is basically a game of numbers and probability. As well as sowing seeds collected from my better performers (I hesitate to use the term elite germplasm just yet), I've also sown seeds from the mixed bag of early pods I collected and whose provenance is unknown. Some seem to pop up vigorous and enthusiastic, others languish and sulk. The latter tend not to make it up through the compost, succumbing before emerging. No doubt I could mollycoddle them more and increase the survival rate, but I actually want robust plants, with an enhanced ability to reproduce from seeds. I also want plants which tuberise under long days, or at least start to get on with it well before the frosts come.

The genetics of all of this are not clearly understood, not by me anyway. Most likely, there are parallels with the potato, where insensitivity to daylength has been linked to reduced levels of Phytochrome B (PHYB) a photoreceptor pigment that plants use to regulate growth and development. In fact it's night length that counts from the plant's point of view, but no matter, the term daylength is in common parlance and I'm sticking to it.

PHYB deficient potato plants have longer stems, with paler leaves, which are broader and flatter; below the soil surface they have reduced stolon formation, so tubers are not widely dispersed, but are clustered close to the parent plant. Crucially, they produce tubers during the long days of summer. If oca tubers form in the same way, I will be looking for tall, pale plants this year. Come to think of it, the best of the 2009 seedlings were tall and pale.

Lavish seed production will hopefully increase the odds of favourable mutations or recombinations appearing. I'll step in again as pollinator-in-chief and come the autumn, I'll select the best and discard the rest. I noticed that the feeblest plants from last year's crop of seedlings gave puny yields; their defective alleles must be deleted from the gene pool forthwith. Exterminate! Exterminate!

Some call it plant breeding, but really it's just vegetable eugenics. I get to create an all-conquering master race of ocas which will go forth and occupy vegetable gardens up and down the land. Megalomania was never so cheap, entertaining and - legal. I'm nothing but a Dalek in dungarees.

I Pot on My Yacons

2010-04-02T09:15:00.005+01:00

Those yacon seedlings are motoring. I turn my back and they're fair busting out of their pots; they need potting on - already; I need more space - now. I suppose I should have seen it coming.

Unlike Baden-Powell and his boy scouts, who are trained to expect the unexpected, I find that the unexpected catches me out every time.That might be because I dodged intoning the pledge: there was never any dyb-dyb-dybbing or dob-dob-dobbing for me. As a consequence, I know next to nothing about woggles and my whittling skills aren't much to write home about either. It could also explain my failure to foresee the germination of those seeds and their subsequent rapid development.

Seeing as how space is running out rapidly, I may as well drop another gentle hint to the universe about that ten acres and associated infrastructure which I asked for in 2009. Last time it sent me respiratory failure and intensive care instead, but hey, isn't faith all about hope in the teeth of adversity?

The logistics of horticulture have always baffled me, but as I'm supposed to be orchestrating this rite of spring - in and out, sowing and growing on - I was hoping for andante non troppo from the yacons rather than prestissimo. They certainly can't go outside yet - the weather is truly atrocious, with wind, sleet, hail and the kind of rain that numbs your forehead and sticks your trousers to your thighs - a typical spring day in other words. If I won't go outside, I can hardly expect my delicate flowers to brave it.

Did I say delicate? They seem to be imbued with the kind of vigour described by the boozy bard Dylan Thomas as "the force that through the green fuse drives the flower". Frank van Keirsbilck, who gave me the seeds, didn't mention anything about lighting any touch-papers and standing well back. Some might call it schadenfreude, but he tells me that he now has twenty yacon seedlings of his own to house. I wish him luck. Honest.

So, as delighted as I am by the sight of these new yacons brimming with life force, I'm hoping I can arrest their development a little bit in order that they remain in their new detached des reses until I can plant them out. Now look here you lot - behave yourselves!

Mushua - A Tasty Transformation of Tropaeolum Tubers?

2010-03-25T22:10:00.001Z

Mashua is one Andean root crop whose flavour is resistant to all my enthusiastic attempts to acquire a liking for it. Every time I see those fat and enticing tubers, my mind fills with desire, yet one taste and my ardour wanes.

That's a pity, because it grows quite well here (watch out for cabbage white caterpillars though) and the yields are often not bad. It throttles weeds with its vigorous, tangled growth and has beautiful flowers.

With an intensive breeding effort for early tuberisation, this plant might have a future as a food in northern latitudes. I know for a fact that seed production is quite possible, if you give it protection from early frosts.

Maybe it's just my incorrigible palate, but prepared simply, by boiling or roasting, it tastes simply terrible. Reading some of the literature, it appears that it needs special preparation - boiling followed by freezing, for example. Perhaps mashua ice cream is a possibility in that case: just add lots of cream and lots of sugar. Following on from my success with yakraut, lactofermented yacon tubers, I thought I ought to explore the same method as a means of rendering mashua more palatable. I mean, people do actually eat this plant as a staple carbohydrate, don't they?

When I was lifting the remnants of the harvest weeks ago, I noticed that some of the frosted tubers had developed a slightly lactofermented smell before decaying further. I wondered whether it might it be possible to arrest decay at this stage and work with these natural processes to produce a more palatable foodstuff.

Lactofermentation of starchy roots is not unknown. In Hawaii, poi is made from cooked and fermented taro corms and is considered a delicacy. Cassava roots can be turned into fufu by the same basic method. Might mashua be similarly converted by the application of this tried and trusted technology?

I grated the tubers and was surprised by the differences in flesh colour between the three varieties.

I sprinkled salt on the layers as I filled the jar, then I weighed it down as before.

I was also surprised by the large quantity of juice that was produced and by its colour - not dissimilar to red wine. Could this be the anti-oxidant elixir we've all been waiting for? That smell, mashua's distinctive signature, quickly persuaded me to abandon all thoughts of imbibing it.

Fermentation was initially sluggish for the first few days, then the room began to smell of something like burning rubber; this was followed by several days of frequent mephitic wafts that wouldn't have been out of place emanating from a Borneo bat cave. Finally the smell subsided, to be replaced by the familiar odour of happy lactobacilli at work. Could it be a case of Tropaeolum tuberosum tamed?

The ghastly logic of what I had started and therefore must complete was clear: I must taste this witches' brew and let my palate decide whether or not mashua's base metal had been converted to gold.

This new product, henceforth to be known as mushua, had a powerful, though not unpleasant smell. So what did it taste like? Well, a bit like sauerkraut, with that peculiar violet perfume taste in the background - moderated, but not eliminated. It wasn't that good, but then, as I manoeuvred a small clump of mushua strands around my mouth, I realised that it wasn't that bad either. I just kept getting the powerful insight that it might be an excellent way of eliminating internal parasites. Hippocrates used to bang on about about food and medicine being interchangeable. Mushua seems to prove it.

Mushua's not going to win any prizes in a taste trial, but the fact that I actually managed to eat what must have been close to a mouthful suggests that I might, just might, be on the right track. Next time I'll cook the tubers first and then ferment them. Or ferment them, then cook them and then ferment them again - there's got to be a way to reach some kind of culinary rapprochement with this tricksy Tropaeolum. Are there any other brave souls out there who would like to share my heavy burden? Mushua is probably just the base camp in a long ascent to Beulah Land, where all bitterness is cast aside. Amen.

Young Yacons: You Like?

2010-03-15T21:55:00.000Z

Ready to stifle those yawns? It's time

to pot on the yacon seedlings I described previously. They seem to be making rapid growth and are in definite need of some extra elbow room. I think I can detect some differences in hypocotyl colouration between individuals - it will be interesting to see if these are maintained in the adult plants in terms of variations in tuber colour.

Their progress has cheered me up - I was feeling a bit depressed by the discovery last week that all my adult yacon varieties must have perished in the big freeze of last winter and have now begun to rot rapidly in response to rising temperatures.

But now back to the the seedlings - I am pleasantly surprised by the vigour of their root systems, shown both individually and collectively here. There's nothing so pleasing as the sight of young roots doing what young roots should - ramifying through the growing medium:

Here they are, post parting, ensconced in their new homes. I'm hoping that any shock or separation anxiety they have suffered will be short lived.

And here's an update shot, taken a few days after the move described above. They're not exactly what you'd call hesitant in exploiting their new found freedom.

Yacon is dead. Long live yacon.

Don't Choke on My Chorogi - Stachys sieboldii

2010-03-10T22:55:00.003Z

When is an artichoke not an artichoke? When it's either Helianthus tuberosus or Stachys sieboldii. The former is the Jerusalem artichoke, neither from Jerusalem, nor an artichoke, although like its namesake, it is a member of the daisy family; the latter is the Chinese artichoke, which does occur in China, but is actually a member of the mint family, the Lamiaceae, rather than an artichoke sensu stricto; true artichokes are naught but overgrown thistles in the genus Cynara. These are Chinese artichokes, freshly lifted. I wonder whether they were the inspiration for the Michelin man?

So the Chinese artichoke isn't an artichoke, but it does come from China - so far, so good. It's a woundwort, Stachys sieboldii, bearing typical woundwort style lanceolate leaves with toothed edges and small spikes of purplish flowers. A common synonym is Stachys affinis. It wouldn't look out of place at the base of a hedge somewhere - let's call its charms rustic and understated; others have referred to it as an invasive brute. Oh and it's also found in Japan where it's known as chorogi and in France where it is called Crosnes du Japon, after the village to which it was introduced from Japan in 1882.

It's simple enough to grow and seems to be a survivor; reasonable soil and sufficient moisture are what's needed for a good crop. Go easy on the nitrogen or you end up with excessive foliage. Last year I rescued a couple of tubers from a friend's garden where they had been growing untended for about ten years - volunteers from a crop I planted there. They got a bit of a bear hug from the mashuas late last year, but despite near total asphyxiation, I've still got a few to replant this spring.

I first became acquainted with this plant in my teens, when I bought a handful from a Chinese greengrocer in London. I loved their maggoty appearance and although I planted most of them, I got to cook a few. They had a nice sweet, nutty sort of flavour and a pleasant texture. I boiled them, although they are often pickled in China; in Japan they're eaten at New Year, again in a pickled form. I've got a bit more sophisticated lately - I often drop them into miso soup where they add both visual and gustatory appeal. That sweet taste comes from stachyose, an oligosaccharide they contain. This is supposed to help feed the bacteria in the gut, with the usual attendant health benefits. Maybe they could be described as "yacon lite". They are also edible raw.

Many people are familiar with the "Three Sisters" concept of multicropping, consisting of maize, beans and squash planted in groups. The post modern version of this is, apparently, the "Three Brothers", a polyculture planting of Jerusalem artichoke, Chinese artichoke and hopniss (Apios americana). I've yet to try this method, but it sounds like it could be fun. The Jerusalem artichoke provides stems for the hopniss to climb up, whilst the Chinese artichoke proliferates into a weedy mass of growth at the base, suppressing all comers - so runs the theory. At harvest time you get a pick and mix of three different different root crops. My experiences with the Three Sisters method have never been very successful, being more like a game of scissors, paper, stone, with one of the three crops overwhelming the others; my guess is that this technique is dependent on suitable varietal selection for success. It's possible that Jerusalem and Chinese artichokes with hopniss might be more successful, as all three are, in their own ways, very vigorous.

Talking of varietal selection, it seems that Chinese artichokes follow the example of the Model T Ford - you can have any variety you want, just as long as it's the standard one. I do recall seeing some tubers for sale that seemed to have a purplish tinge to the emerging shoots, but this may have been a stress response rather than an indication of genetic variability. So we're limited to just the one variety in Europe, as far as I can tell.

The National Institute of Horticulture (INH) in Angers, France had a stab at breeding the plants back in 1980s and 90s, but I don't know what progress was made. What they did show was that plants are capable of producing viable seeds. That's good, because in order to escape that most hateful of designations, "minor" root crop, some serious work needs to be done on increasing the dimensions of the tubers. In the world of root crops, size matters. Those of a squeamish nature may recoil, but I would also be interested in seeing whether the judicious application of colchicine might induce chromosome doubling and lead to bigger tubers. Anything much smaller than thumb size is never going to endear itself to the phyto-philistines out there, so it really is necessary to pump them up a bit.

I propose we set up a Chinese artichoke improvement group to get hold of some more Stachys sieboldii germplasm, then cross them indiscriminately and select the progeny for tuber size and yield. Call it recurrent mass selection if you like, just as long as you get on with it.

You Can With a Yacon

2010-02-26T20:44:00.021Z

It seems like another piece of received wisdom about Andean root crops must now be decapitated and left for dead in a ditch: that viable yacon seeds are hard to produce and hard to germinate. I used to subscribe to this view - until last Monday in fact. No longer. Like these newly emerging yacon seedlings, I've seen the light.

Speaking botanically, these seedlings issued forth from achenes - hard, dry fruits, looking like mini versions of black sunflower "seeds", to which they are structurally very similar. You may also see the term cypselae used to describe these non-juicy fruits. We'll let the botanists tussle over the validity of one versus the other - they're pretty much identical.

The yacon-sunflower similarity doesn't stop at the seeds - sorry - achenes. The flowers, as shown here, betray their common ancestry: both belong in the daisy family, the Asteraceae. Yacon's blooms are a shy, retiring version of the sunflower's in-your-face boldness, which seems strange, given its prodigious vegetative performance.

Anyway, I was a bit dubious about these seeds when they arrived in one of Frank van Keirsbilck's regular (and irresistible) parcels of horticultural temptation last autumn; he's the devil in disguise.... They had a certain dusty, funereal aura about them and I duly forgot all about their existence until around two weeks ago. Then, during a febrile bout of rationalisation, I rediscovered them. Grow or go, I thought as I tossed them onto some moist paper towel to imbibe.

The latter seemed more likely when they became totally covered in thick mould growth less than a week after sowing. But hold on - peering through the fungal fog, I noticed, with something akin to disbelief, that several of them were actually germinating. Result!

I claim no credit whatsoever in this success, other than the fact that I finally found the necessary motivation to actually sow them. They came from Frank's plants in Belgium and are the result of crosses between some of his varieties. Just like with oca, it appears that if you've got the right combination of varieties, seed production isn't that difficult to achieve. It will be interesting to see how they turn out, if I can get them through those awkward first few weeks of life. To the uninitiated, all seedlings look the same. We know different. Prepare to stifle those yawns when I accost you with the regulation boring baby snaps in due course.

And Now For Something Completely Different

2010-02-20T16:30:00.003Z

- which has nothing to do with the Liberty Bell, John Philip Sousa or Monty Python in this instance. I mentioned previously that interspecies crosses have a useful role to play in the development of new crops.

Well, here's an illustration of what might be achieved and some of the challenges inherent in this sort of work. Not in this case a root crop - I do actually allow myself the luxury of growing a few other plants. This was a little impromptu experiment in creating a hardier squash.

Chilacayote (Cucurbita ficifolia) is by far the most vigorous and cool weather tolerant squash that will grow outdoors in Britain. As the autumn proceeds, chilacayote keeps on going, setting fruit, whereas none of the other squashes can cope with the cool wet weather that typifies our late autumns - they splutter to an undignified end months earlier. I thought it would be interesting to try and combine the exuberance and fecundity of the chilacayote with the culinary superiority of the related species C. maxima. Chilacayote also has a knife-bustingly tough shell which allows it be stored for ages - several years, in fact. That, too, would be a useful characteristic to transfer to a better quality squash.

In 2007 I pollinated a female chilacayote flower with a male C. maxima variety. To my surprise, the fruit developed and contained seeds which were intermediate between the two parental types. I planted these the following year. Several germinated and the F1 seedlings grew away vigorously, with an initial appearance somewhat like C. maxima:

I planted them out after the last frosts and they romped away.

They produced plenty of female flowers, but male flowers were rare and the anthers didn't seem to produce any pollen. I pollinated individual female flowers with pollen from either C.maxima or C. ficifolia - a process known as backcrossing. Plenty of fruits developed on the backcrossed plants, although no viable seeds seem to have been formed in any of the fruits I have examined so far.

Shame. I've still got a few left though and I daresay I'll open them up this spring, just in case. I'm tempted to blag my way into a local institute of higher education and see whether I can regenerate the plants in vitro using some of the fruit flesh, which is, of course, maternal material.

Anyway, here's the family tree laid out in the way beloved of plant breeders, with mum on the left, dad on the right and some of the interspecies offspring beneath in all their motley glory:

So that's as far as my squash breeding project has got to date. I contacted a cucurbit breeder in Slovenia, Dr Anton Ivancic, who expressed surprise that I had managed to produce any F1 seedlings at all - he normally has to excise the embryos and grow them in nutrient media before planting them out. He looked at my pictures and concluded that that there were definitely some C. maxima genes in there. His paper on Cucurbita ficifolia x maxima is here. The flesh of my fruits appears to be identical to C.ficifolia; the only difference that is obvious seems to be in the yellow skin colour.

I'm particularly fond of one of these fruits, which is large and smooth and shapely. I fondle it with a frequency that borders on the peculiar. Not so much the love that dare not speak its name as the love that doesn't yet have a name - ficifoliaphilia perhaps?

There is a link, somewhat contentious, between chilacayote and tuber crops: spermidine synthase genes derived from C.ficifolia have been used to genetically modify sweetpotatoes in Japan. The resultant transgenic plants are apparently more resistant to chilling injury and oxidative stress. They are also able to develop storage roots (the bit you eat) in lower light levels than normal sweetpotatoes. No mention of what they taste like though. So whatever your opinion on GM technology, it at least shows that C. ficifolia is a plant with some very useful attributes. Maybe if I keep crossing it with any other squashes that I happen to be growing in the patch, I might just get lucky and create a delicious new squash that climbs trees, thrives in cool weather and keeps for years. I have a dream............

Revealing My Hidden Talets

2010-02-13T15:08:00.001Z

I was scratching around disconsolately in a large pot where one of my yacon varieties ought to have been. Illness and inclement weather struck at a critical moment in 2009 and now all I could find was mush. It was a beautiful sunny day, although the wind was bitter. My mood darkened as a bank of clouds headed in my direction. Seemed like a hard rain was gonna fall......

Then I remembered that a stray Amphicarpaea had appeared in that particular pot during the summer and had proceeded to climb and twine its way through the yacon foliage with abandon. It occurred to me that maybe I ought to redirect my attention towards locating any of the subterranean seeds - hog peanuts - that might be lurking amid the decay and destruction.

So I did. After a few minutes sifting through the soil, I had several of the large seeds in the palm of my hand. Not a meal's worth, I grant you, but in the world of out-there edible plants, an acceptable haul and not a single mushy one.

The thin pods (technically pericarps) were easily rubbed off to reveal the distinctive bean like markings on the seed coats. Here are the self same seeds - certainly nothing like peanuts. Underground beans is nearer the mark, hence my adoption of the name "talet", which is used in Puebla, Mexico by some of the local people who consume this plant. It means "soil bean" in the Nahua language, which is wholly appropriate I'd say.

As I've been calling them talets, I decided to cook them in the traditional Mexican way, on a hot plate. This was described in Francisco Basurto Pena's paper in the October 1999 edition of Economic Botany, the source for much of my knowledge of this plant. The toasted beans were actually rather tasty like this - I've always boiled them before.

Suffice to say that they're really quite nutritious, in a beany sort of way. Think of them as underground French beans and you won't go far wrong.

Although the yield is nothing to write home about, this is a wild plant, far from its native lands, which will survive the winter here and then grow and produce a tasty crop. There are plenty of other plants in my collection that could learn a thing or two about manners from this humble peanut that isn't.