Monday, 16 September 2013

Experimenting With Tuber Crops in Devon

Well, well.... as we're nearing the end of another growing season, it's soon going to be that exciting time again for us to trade plants for next year.

This season I've been experimenting with just about all of those fascinating tuber crops that you can grow in the UK -  Mashua, Oca, Yacon, Chinese Yam, Chinese Artichokes, Jerusalem artichokes, Ulluco and Ground Nuts (Apios Americana - not peanuts!) These are particularly interesting crops for me, as the search continues for perennial food crops that could replace annuals as part of our staple diet.

File:Yacon plant (Smallanthus sonchifolius).JPG
Yacon growing in their native Andean Region
It's still difficult to know what's going on under the ground and what the harvest will be like, but I'm expecting a decent crop from the Yacon (Smallanthus sonchifolius) - which seem easy to grow, even in some shade but demand plenty of food and water.

As with many of these Andean tubers - yacon are day length sensitive and so only start producing tubers after the autumn equinox (September 21st) - so we have to rely on a long mild autumn for a good harvest.

Oca - a tuber crop and a salad! The leaves have a lovely lemony taste
Oca (Oxalis Tuberosa) is another of those day length sensitive crops but have also done really well, even in quite dry soil, and I'm hoping for a good yield. I've also been enjoying tossing their tangy leaves into salads and sandwiches this summer, yum!

The Mashua (lots of info in last year's posts) have been suprisingly tricky this year, compared with last and have appeared not to have enjoyed all the hot, dry weather, (or cabbage white caterpillars!) but I'm still hoping for a good few tubers.

Also disappointing have been the Chinese yam (Dioscorea Batatas) and Ulluco (Ullucus tuberosus), but I suspect that they may be suffering from the opposite problem - being too demanding of sunshine and warmth to grow very well in most of the UK. Only my plants in the polytunnel look healthy... Mind you we are up at 180m above sea level in North Devon, so have cooler summers than much of Southern England. Ulluco can also suffer from the same viruses as potatoes, so I wouldn't be at all surprised if an infection has stunted their growth.

The Ground Nuts are now rambling up a south facing hedge very happily after a slow start, it seems they need lots of water to grow vigorously. What a promising crop though - nitrogen fixing and very hardy, I'm excited by the potential of these guys. I probably won't attempt to dig any up until they're well established next autumn though.

As I say it's still early days, but I'm expecting to be able to share Oca, Yacon, Mashua, Jerusalem Artichokes, and hopefully a few Chinese artichokes with others in November/December. If you're interested to do a plant swap or to make a donation towards my forest garden project in exchange for some tubers, please get in touch!

Mashua can produce beautiful edible flowers late in the autumn too! Thanks to my uncle Dan for the picture.


  1. Hi Charlie. Great site! I'm a forager on the North Coast of western North America (British Columbia, Washington), where our growing conditions and wild plants are very similar to yours. I'm intrigued by your experiments; I've wanted to try eating and growing these Andean tubers for years.

    Have you tried evening primrose roots? (Not a tuber, but an interesting subterranean edible.) They make intriguing pickles, kind of purplish, with a faint horseradish snap. The flower is beautiful, and the young shoots are edible too. They grow exuberantly around here, and are common in our flower gardens.

    I wrote a book about this stuff a few years ago, called "The Neighborhood Forager". (Sorry about the misspelling; Yank publisher.) Many of the plants you mention here are in it: daylily, kousa dogwood, gingko, hawthorn, Tropaeolum... For what it's worth.

    Anyway, just wanted to leave a shout from the far side of the planet. Really like your blog!

    Rusty Ring: Reflections of an Old-Timey Hermit

    1. Hey Robin, great to get your message, thanks!
      That's funny, I know of another Robin - who has written books about foraging in the UK - Robin Harford - check out his recipes here!

      If you don't have it already, I really recommend getting a copy of Martin Crawford's 'Creating a Forest Garden' where there's loads of fascinating information on these kinds of plants and how to grow them...

      Shame you're so far away as I'd love to send you some of the tubers to try for yourself.... I'm sure you can source them in the US though?

      Best wishes friend,


  2. Thanks for the info, Charlie! Really liked Robin Harford's site. Lots of good seaweed posts there. That's one of my subjects, but good info is hard to find, especially for anything not eaten in Asia. Fortunately we have a lot of seaweeds in common between the UK and the North Pacific.

    Deep bow,

    Rusty Ring: Reflections of an Old-Timey Hermit

  3. Thanks for the great post on your blog, it really gives me an insight on this topic.
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