Yacon tubers

Over the last few years there has been increasing interest in unusual edible plants. One of the big advantages in having an allotment or a large garden is that it gives you the space to experiment with new tastes without having to sacrifice any old favourites, but some of the exotic specimens can be very tricky to grow.

So if you’d like to branch out and try something new this year, but you want something with a reasonable chance of success (what’s the point, if there’s no harvest at the end?) then here are six relatively unusual plants that should crop well on an allotment.

  1. Chinese artichokes (Stachys affinis), often called Crosnes. Jerusalem artichokes are common on allotments – they’re low-maintenance plants that enjoy the space and produce a reliable harvest most years. Chinese artichokes are grown in a similar way (from seed tubers) and can be planted out from November through until April (about 3 inches apart). They’re much smaller plants, growing to only 18 inches tall. If you create a permanent bed then you can leave a few tubers in the ground to grow next year. If you’re rotating them around the plot then it’s useful to know that they’re in the mint family. The tubers are lifted and used in the autumn and winter, and can be eaten raw or in stir-fries.
  2. Yacon (Smallanthus sonchifolius) is another unusual tuber crop. It can be a bit hard to track down plants, but it’s well worth the effort as you’ll get surprisingly large tubers with very little effort. They’re crisp and sweet and can be eaten raw, or used as a substitute for water chestnuts. Crowns can be dug up before the hard frosts and potted up over winter – if you can keep them frost-free they can be planted out again the following spring. Yacon has beautiful, large and furry leaves and grows to around 3 feet tall. It has yellow flowers, but they appear late and the plant may be cut down by frost before they open fully.
  3. Tomatillos (Physalis ixocarpa) are the fruits used in a traditional Mexican salsa. Grown in a very similar way to determinate tomatoes, the mature fruits are either green or purple and come in a papery case. Most successful under cover, they are not as productive as tomatoes – but on the flip side they are not defeated by blight.
  4. Inca berries (Physalis peruviana or P. edulis, also known as physalis, cape gooseberries or goldenberries) are a close relative of the tomatillo. Grown in the same way they produce a harvest of small, sweet orange berries that remain in their papery cases and are therefore usually immune to pests. They fall from the plant when they’re ripe, and look very impressive as part of an exotic fruit salad. They’re also nice cooked, though, mixed with more prosaic fruits or turned into jam.
  5. Achocha (Cyclanthera pedata or C. brachystachya) is a vigorous climbing plant in the same family as melons and cucumbers, but in terms of care it can be treated more like climbing French beans. It is happy outside once the risk of frost has passed, and needs something for its tendrils to cling onto. Pale flowers that are much loved by hoverflies are followed by green tear-drop fruits. These can be eaten raw and whole when young; older fruits have hard seeds (easily saved for next year) that need to be removed, and are best cooked. The versatile fruits can be used like green peppers, or pickled like gherkins.
  6. Hardy kiwis (Actinidia arguta) are good if you have a suitable spot for a perennial climber (against a wall or fence). Fruits are smaller then the kiwis we are used to, but the plants are hardier and the fuzz-free skins mean you can eat the fruits whole. If you only have space for one plant then ‘Issai’ is the self-fertile variety you should look for. As with all perennials, hardy kiwis may take a year or two to become established, but once they do they should be very productive.

Most of these plants are relatively well-known and widely available, but when you step off the beaten track it’s important to remember that not all plants are edible, and that some edible plants have poisonous parts. To avoid any problems, source your plants from reliable suppliers, do your homework, make sure the plant that grows is what you expected, and always try new foods in small amounts at first.

This post first appeared on the Reader’s Digest Gardening blog in April 2011, but sadly that blog has now disappeared.

And if you are interested in growing unusual vegetables, you’ll love my new book, Jade Pearls & Alien Eyeballs, which is all about unusual edibles and the people who grow them.