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I HAVE just finished one of the few winter jobs at my allotment: preparing my rhubarb patch, including setting up one of the plants to be forced. This means covering it with a large container to make the stalks grow more quickly in search of light.

If you have the space, I highly recommend getting a few rhubarb plants as they are so easy to grow. I give mine little attention, but each spring they produce a huge crop when there isn’t much home-grown produce around. Technically, rhubarb stems are a vegetable as they are the plant’s leaf stalks, but they need plenty of added sugar to combat their acidity, which is due to a compound called oxalic acid. So, when it comes to cooking, they are used as a fruit.

Forced rhubarb is sweeter than the ordinary kind as it has less oxalic acid. The forced stems are also pinker because plants can’t make the green pigment chlorophyll in the absence of sunlight, which makes for nicer-looking desserts. But the chief advantage of forcing rhubarb is that the stems can be harvested sooner, as early as February in the UK, while those left unforced can take a month or two longer.

It is possible to buy elegant, terracotta forcing pots to exclude the light, but, for economy, I use an old, black rubbish bin with duct tape over any holes or cracks and a large brick placed on top to weigh it down. To speed up growth, you can also insulate the rhubarb plant by covering it with straw or by wrapping some old carpet around the outside of the bin.

Now would be a good time of year in the northern hemisphere to plant some rhubarb crowns, so long as the ground isn’t frozen. Ten years ago, I planted five in a row and pegged down a metre-wide roll of weed-suppressing membrane over them, with crosses cut into it so the top of each plant could poke through.

Every winter, when the plants’ leaves and stems have died off, I feed them with rotted horse manure or a helping of fish blood and bonemeal. Then, I simply plop my dustbin over the top of one of them. The forcing process weakens the plant, so don’t do it to the same one for two years running, and only begin once the plants are well established.

When the time comes to harvest your rhubarb, rather than cutting or snapping the stems, just pull them off by gently twisting from the base. This encourages the plant to put up more shoots in the future. Don’t eat the leaves, as they have such high oxalic acid levels they are poisonous.

By boiling or baking the stems with sugar to taste, you can turn them into a crumble, fool, pie, tart or compote. Or make rhubarb and custard ice cream, which you can do by layering dollops of the two components in a plastic tub and putting it in the freezer for 2 hours. Serve semi-frozen, ideally with thin ginger biscuits.

Clare Wilson is a staff writer at New Scientist and writes about everything life-science related. Her favourite place is her allotment @ClareWilsonMed

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