Down on Plot #59, Jo and I are always keen to expand the range of edible crops that we grow, especially anything that stores well and can be used over winter, when there’s usually a lack of fresh stuff to harvest. This year I decided to try three South American tuber crops that I’d heard about: Yacon, Oca and Ulluco.
Smallanthus sonchifolius produces large, crisp (some say brittle) tubers that, based on the pictures at downtheplot.com look a lot like Dahlia tubers. According to Mark Diacono, writing for The Guardian back in 2010, they’re crunchy and sweet-tasting, and can be eaten raw in salads, or as a snack. Sounds great.
I bought a pack of growing tips from The Real Seed Catalogue and started them off in pots in March. I potted them on when they started to sprout and then planted them out in large plastic tubs last month. A few sources had suggested that ground-grown Yacon can be difficult to harvest due to the tubers’ habit of snapping too easily, but turning them out of pots was a lot easier.
Harvesting should take place just after the first frost, before any prolonged cold spell has a chance to damage the tubers. So that’s a job to do around the same time that I’ll be lifting and storing the Dahlia tubers.
Oxalis tuberosa is a relative of the wood-sorrel that develops clusters of small, knobbly, often brightly-coloured tubers. They’re growing in popularity, with organisations such as the Guild of Oca Breeders working to spread the word. The tubers can be eaten raw or cooked much as you would a potato: roasted, boiled or mashed, they’re apparently quite sweet-tasting.
I bought a variety called ‘Dylan Keatings’ from The Real Seed Catalogue and was sent six or seven smallish tubers. I started them off in large modules and three of them sprouted into strong, healthy-looking plants.
Once again I followed the advice on Downtheplot.com and planted them out on ridges of soil. Oca tubers don’t start to form fully until after the first frost has killed the leafy part of the plants. Leaving them a couple of weeks after the first frost could mean levering them out of cold, wet mud, and the process is meant to be much easier if you can dig them out of a ridge instead.
Ullucus tuberosus, the third of this year’s new tuber trio, is very similar in appearance to the potato, but in a much wider spectrum of colours, from golden yellow to pale green, to bright pink. Once again they can be eaten raw, as well as cooked as you would a new potato.
My stock came from Incredible Vegetables, and I’ve been following the detailed growing advice on their website, along with added notes from Downtheplot.com (very useful site, that. I wonder if it’s still being updated?) As a result, the plants are currently in pots in the greenhouse, pending planting out once the current spell of grim weather seems to have safely passed. I might even wait until I’ve harvested this year’s garlic and re-use that part of the plot.
Late November to December is harvest time, and they do need to be earthed up, so I’ll grow them on ridges as well.
Jo and I are looking forward to trying all three of these new tubers over the winter. We might even give Dahlia tubers another go and make it a foursome.
If you grow them regularly yourself and have any top tips on cultivating the best crop, please do leave a comment below. Any advice would be very gratefully received.