WHAT is to become of Comrade Corbyn’s allotment? I know that’s what you’ve all been worrying about these last few weeks.

Supposing Jeremy is so busy being our prime minister-in-waiting that he doesn’t have time to keep up his plot, and gets cited by the site committee? It would be a public relations disaster.

The solution is to concentrate on crops which can survive neglect for long periods. One that comes to mind is the potato onion. Better known in Ireland and North America than it is over here, it’s a larger cousin of the shallot, strong in flavour and useful in salads or cooked dishes, but especially valued for pickling. And once you’ve planted them, in autumn or spring, you don’t really have to do much else to them until harvesting in summer.

Finding stock of potato onions, a type of “multiplier onion” started from sets not seeds, can be difficult, though a bit of time spent searching on the internet will often turn them up. For instance, Poyntzfield Herb Nursery (www.poyntzfieldherbs.co.uk; tel 01381 610-352) usually has some available for mail order at this time of year.

Choose a well-drained, open-textured piece of land, preferably in a sunny position — the sets won’t survive waterlogging. I usually plant mine in October or November because I think they grow larger from an autumn start, but if your garden doesn’t drain well over winter you might be better waiting until March. If available, spread a good layer of compost or old manure over the ground after planting.

Place each set in the soil about nine inches apart. Whether you should bury them, or leave the top third of the bulb showing, is a matter of much debate. An alternative name for potato onion is underground onion. I put them about an inch below the surface of the earth, mainly to prevent birds pulling them out. Some gardeners bury them to begin with, but then scrape back the soil in April to expose them to the sun, which is supposed to help them ripen. I’ve never bothered with this, as I find that they ripen and store very well in any case.

If grown in good soil, potato onions are unlikely to need watering except perhaps during long periods of drought in late spring or early summer. Other than the occasional run along the row with a hoe to keep the weeds down, there’s no other attention needed.

Once the green foliage has withered in summer and the outer covering of the bulbs is brown or red, lift the clumps gently with a garden fork and leave them somewhere sunny and airy to dry. For storage, the clumps are separated into individual bulbs and kept indoors, cool and dry.

Keep some bulbs to plant for next year’s crop. Small sets tend to produce a small number of large onions, while larger ones yield a large number of small bulbs, so it’s worth selecting a variety of sizes for replanting.