Come on Kumara!

The connection between a convolvulaceous tuber bearing crop, a folk-blues artist and a cetacean may seem somewhat obscure, but let me elaborate. I used to enjoy working my way through my dad's old records; he seemed to think it was all part of the process of a liberal education and was content to let me wear out the stylus in the pursuit of musical enlightenment.

The link is Leadbelly's 1944 recording of "Tell Me Baby", which my dad had on an old LP. In addition to Leadbelly's 12 string guitar, he was accompanied by a funky zither, or more correctly a dolceola, played by one Paul Mason Howard. The song includes the following lines:

"The whale begin to wiggle and Jonah begin to scratch,
The whale throwed Jonah in somebody's sweetpotato patch".

Intrigued by this botanical reference, I duly trotted off to the Oxford Book of Food Plants to learn more about sweetpotatoes, so that I could fully conjure this absurdist image in my youthful mind's eye. Back in the antediluvian days of my childhood, sweetpotatoes were a rarity in the shops in the UK and I certainly hadn't eaten one. Still, at least I now knew what they looked like - both above and below ground.
Sweetpotato availability has improved immeasurably since those days and although I haven't had more sweetpotatoes than you've had hot dinners, I have enjoyed them in numerous hot dinners myself.

The logical next step is, of course, to grow one's own , although they are generally considered a warm weather crop and warm weather is the exception, rather than the rule in the UK. When Ulrike Paradine sent me a picture of her crop in, I think 2003, it was obvious that Radix could ignore the potential of sweetpotatoes no longer. You don't get many of these to the pound missus:

Kumara is the Maori name for them and might possibly be a better one than sweetpotato. I remember Kay Baxter of Koanga Institute in New Zealand showing us her collection of Maori varieties on a particularly wet and windy Northland afternoon. Kay told us that some varieties were particularly favoured as food for the elderly or infirm; others were grown in baskets then moved around by canoe as offerings to various gods. I forget the exact details - rain stopped play.

So this year I decided to have a go at raising a few sweetpotato varieties. 'Tainung 65' is acknowledged to be the best grower in our climate and is available from a number of suppliers. I got mine from Ulrike, who also supplied me with 'Beauregard' another supposedly superior variety, along with a variety she bought in Beta, a German supermarket; Frank van Keirsbilck also chipped in with a donation of a red fleshed variety, whose name is unknown, so I'll just call it Frank's. I didn't manage to get hold of 'Georgia Jet', which is a highly regarded short season variety. Maybe next year. Wandering aimlessly in a local supermarket, I found myself strangely drawn to the stand with the sweetpotatoes. There I found a variety called 'Kumara', with visible sprouts. I couldn't resist giving it a go, remembering, fondly, our encounter with the Maori varieties in Aotearoa. On perusing the packet, I found that they were not from New Zealand as the name suggested, but the USA. A friend gave me a plant she'd got from a friend, no idea what variety it was, but known henceforth as 'Claire's'. Six varieties in total.

As we've had another wet, cool, sunless summer, this might be a good time to sort the men from the boys. To paraphrase Frank Sinatra: "if they can make it here, they can make it anywhere". Due to other commitments, I was also very late in getting them planted out. What better way to test their suitability for our climate? In addition to my as yet unfulfilled desire to grow the high altitude New Guinea sweetpotatoes (are you listening Universe?), I'd also like to try culina (Ipomoea minuta). This is a high altitude Andean species, with pleasant tasting tubers; I'm still hunting for a source. I'm not entirely clear as to whether the evocatively named Huachuca Mountain morning glory (Ipomoea plummerae) from the mountains of South Western USA, is a variety of, or synonym for I. minuta; it too is edible and hardier than the average sweetpotato, Boo Boo. Don't know if it's found in Jellystone Park as well as Arizona.

I'm wholly ignorant of Frank Sinatra's horticultural exploits, if any, but if I may misquote again from Ol' Blue Eyes' canon: now the time has come and so they face the final curtain. I can delay their harvest no longer. If the frost don't get 'em, the rodents will.

Brace yourselves: here are the results:







The last can be excluded on the grounds that it arrived as a rooted plant which I hastily thrust into the ground: the impressive looking tuber probably represents two seasons' growth rather than one, which kind of knocks it off its pedestal somewhat.

It seems that our indifferent summer has got the better of the sweetpotatoes this year. They can join the ranks of the heroic failures and also-rans that have punctuated my horticultural career. Had Jonah been thrown into my sweetpotato patch, I don't think he'd have had a particularly soft landing as the vines were a bit thin on the ground; he'd also have been one small meal from starvation. We just didn't have enough warm and sunny weather at the right time. Living in the southwestern extremity of Britain, on a bony finger jabbing defiantly into the Atlantic swell, I can hardly expect any better. Frank and Ulrike tell me they have had more success. Still, I haven't given up - yet.


Jeremy said…
Garrett Pittinger (sp?) in Canada was developing some varieties for a short season there, but I think he gets more degree days than you do.

Still, at least now you know.
Rhizowen said…
Thanks for that Jeremy

I also wonder whether Washboard Sam's 1939 blues hit "Diggin My Potatoes" is actually referring to Ipomoea batatas rather than Solanum tuberosum.'+My+Potatoes

Are the "vines" which are being trampled on in the song actually what we would refer to in the UK as haulms? Perhaps an American could enlighten me.

I think I knew that sweepotatoes would be a bit of a non-starter, especially in a bad summer, but I couldn't resist the temptation. I'm sure you're right about the lack of degree days. Ken Allan, author of "Sweet Potatoes for the Home Garden" was also attempting to breed better northern climate sweetpotatoes by crossing short season varieties with cool weather tolerant long season varieties. I think he gave up. "Hotter than July" Stevie Wonder's platinum album of 1980 was not,I assume, inspired by his experiences of a UK summer. Maybe the fabled New Guinea varietes would be better adapted, or even "Camote Morado", an accession in the CIP genebank which was collected at 3810 metres asl and which is, sadly, currently unavailable.
Hi owen, sorry i havent been in touch for a while...its been a very interesting couple of months!
I thought you might like a peek at my efforts at growing sweet potatoes, i decided to have a go at hotboxing in one of the cold frames at Ryton. As i couldnt find a supply of organically registered horse manure i made my own recipe of one third cow dung, one third straw and one third fresh grass clippings. The variety was T65 and came as slips. Planted out approx early june, they were harvested late Sept 2008
here is the pic

hope your keeping well, spk soon lou x
Rhizowen said…
Hello Lou

Nice to hear from you. How are the ullucos doing? Your T65 looks better than mine - I expect all those gentle breezes blowing in from the A45 might be something to do with it. I like the hotbox idea - perhaps you could combine melons (or pineapples) with sweetpotatoes for above and below ground yields.
Anonymous said…
Fantastic blog you've created here. Really brilliant, with some stunning successes at growing obscure stuff.
Anne-Marie (UK/Papua New Guina)
Rhizowen said…
Hello Anne-Marie

Thanks for your kind comments. I've had some stunning failures too.

Naturally when I see someone with an address in Papua New Guinea, I get all excited about potential future collaboration........
Anonymous said…
:-) Sure, drop me a line. I'm a botanist by background and work as a volunteer in coastal Madang...always looking for something interesting and planty. In case anyone hasn't read about the crops of New Guinea (lots of incredible obscure stuff...for example, pitpit and pandanus as staples), do read Bruce French's excellent books (freely available for legit download)
gregoryannemarie at gmail nospampleasedotcom
Rhizowen said…
Girl, you really got me going, you got me so I don't know what I'm doing.......

Thanks very much Anne-Marie for the link to Bruce's books -an ideal blagger's crash course on New Guinea crop diversity- and for introducing me to Food Plants International.. I haven't started on 18,000 species in the database yet.

Pitpits and pandanus as staples - I wonder whether they'd grow in Cornwall? Been wanting to try them for years.

Oca and ulluco have been attempted in PNG in the past I believe. Should do well at potato altitudes. There's plenty of other stuff I can think of that might be worth attempting. I'll be in touch.
Mybighair said…
I grew Georgia Jet this year. Not great results, but I can spare you a tuber if you want it for slip production.

I plan on growing them as ground cover under the tomatoes in the poly-tunnel next year.
Rhizowen said…
Hi Mybighair

Thanks for that offer. I may take you up on it......
Ground cover in the polytunnel - yes, although be careful not to let the spreading shoots root or you'll end up with masses of spindly little roots rather than big ones. A bit like my outdoor crop. It might be worth trying some of the ornamental varieties like Blackie or Blackheart (I think) - the roots are edible.

Despite the blurb in various seed catalogues about sweetpotatoes growing well all over Britain, they neglect to mention the necessity of parking a whopping great big greenhouse or polytunnel over the top the plants. I'd be fascinated to hear from anyone in Scotland who has successfully grown sweetpotatoes outdoors. Come on somebody, surprise me.
Rhizowen said…
This comment has been removed by the author.
Mybighair said…
I grew the Georgia Jet three different ways this year. In open ground, under a cloche and in the poly-tunnel. The ones in the open ground were comparable to Kumara, so pretty much a waste. But the cloche and poly-tunnel plants were more worthwhile.

I wouldn't give them a space of their own again but as a catch crop under the tomatoes they may be worth perusing.

I also tried three of the ornamental types this year.

Blackie did OK in the poly-tunnel and I plan on trying it again, but it's not near as good as Georgia Jet.

The yellow and the variegated forms produced nothing worth having so I won't be bothering with them again.

I don't honestly believe any of the varieties currently available are going to produce a viable crop in the UK. Even under cover they are disappointing at best.
Rhizowen said…
Can't seem to get your email address to work Anne-Marie. I think I've tried all likely permutations of the one you've given me. I wonder what I'm doing wrong?
Anonymous said…
Your writing is spectactular! Thanks for the laughter, when I needed it most. :D Here's to a better growing season for your sweetpotatoes next year...

Ottawa Gardener said…
Wet, sunless summers.. we had one similar to that which stunted the vining crops.

I've grown Georgia Jet in Ottawa and it did very well though I mulched with clear plastic as per Ken Allan's northern sweet potato book.

I've not had a crop failure yet but I didn't grow them this year so they haven't been truely tested.
Jay said…
Beauregard is a very good variety. I believe Purple Delight (aka Purple Alabama) might grow fast enough to prove viable storage potatoes in your area. I planted mine in mid-late may and did very well (

I have found that if a gardener wants to make seed from sweet potatoes it requires replanting an already mature tuber in the ground for a second season. The roots become very woody, but hybridizing of various varieties can be completed this way.