Following our success with forcing chicory, we’ve turned our attention to our rhubarb crowns. Forcing rhubarb is a notable tradition in the UK, providing bright pink, tender stems to harvest at a time when there is little else to be dug out of the ground.
You may have heard of the ‘rhubarb triangle’ – not a place where rhubarb mysteriously vanishes, but rather an area in West Yorkshire bordered by Wakefield, Rothwell and Morley, where rhubarb is grown in special darkened, warmed sheds and forced to produce early stems between January and March for UK shops. Lit only by candlelight, the sheds house 1000s of rhubarb plants which send out long slender shoots in search of light. You can even take a Yorkshire rhubarb triangle tour, during which you can even hear the fast-growing forced plants popping if you listen closely. Forced rhubarb from this area of Yorkshire has been granted Protected Designation of Origin (PDO) status by the European Commission.
With our two young rhubarb plants, we won’t be forcing on quite the same scale, but the same principles apply. As with chicory, the process deprives the growing plants of all light. The resulting stems (rhubarb) or leaves (chicory) are pale and more tender, more delicately flavoured than those grown in the tough outdoors. The darkened plants will also grow faster, desperately hunting for light in order to photosynthesise and convert sunlight to energy.
The best time to start forcing rhubarb is when you can just see the first signs of new growth at the turn of the year. Up-end a large dark-coloured pot, or bucket, one that is big enough to accommodate the growing stems, over the whole rhubarb crown. Pin it down into the soil with pegs, so that a) there’s no danger of the bucket blowing away in a winter storm, or b) no light gets in between the edge of the bucket and the soil. Any drainage holes in the bottom of the pot must be blocked off to stop even those pinpricks of light from getting in. I usually cover them with stones or concrete slabs, which has the dual effect of blocking light and again weighting the pot down so it doesn’t blow away.
Try to do this during a spell of dryish weather so that the embryonic plant isn’t wet when you cover it with the pot. Also don’t cover the rhubarb when the ground is frozen or the covered plant will remain too cold. It’s also a good idea to give the plant a quick onceover for slugs, woodlice and the like.
You can now leave nature to take its course. Check the plant every couple of weeks for growth and in 4-6 weeks you should be cutting your own forced rhubarb. The forced stems are generally less fibrous and slimmer than ‘normal’ rhubarb stalks, and also a bright pink – the colour of Pepto-Bismol rather than the darker crimson of stems grown outside in summer.
The incipient leaves should be removed as these, like their outdoor grown counterparts, are poisonous. Then the forced stems can be used in cooking just as you would for any rhubarb – poached, in a fool, or as a savoury accompaniment to meat or fish. Or treat yourself to a classic rhubarb crumble with MsMarmiteLover's recipe.