A celebration of rhubarb

Forced rhubarb (Callie Jones)

Rhubarb is, of course, familiar to pharmacists of the older generation as a laxative. In use for 5,000 years, the drug is prepared from the rhizomes and roots of an Asian species, Rheum officinale, or medicinal rhubarb.

The Rheum genus contains about 60 species, including others used as laxatives and two whose leaf stalks are commonly used in cooking — garden rhubarb, R rhabarbarum, and false rhubarb, R rhaponticum, which, despite its vernacular name, is a true rhubarb. Shop-bought rhubarb is generally a hybrid, usually described as Rheum x hybridum.

Rhubarb was first grown in Britain in about 1777 by a Banbury apothecary, William Hayward, who planted seeds sent from Russia.

But why is rhubarb celebrated in Wakefield? I’ll tell you why. It is because the city is the southern vertex of West Yorkshire’s famous rhubarb triangle.

Although often thought of as the 70-square-mile triangle between Wakefield, Leeds and Bradford, the true rhubarb growing triangle is a much smaller area between Wakefield, Morley and Rothwell, covering just nine square miles. Only a few decades ago, more than 90 per cent of the world’s forced rhubarb crop was grown in this compact wedge of land.

Rhubarb growing began here because the area offered ideal conditions for large-scale cultivation — suitable soil, sufficient rainfall, supplies of soot and ash, and cheap fuel to heat the forcing sheds, where the rhubarb is grown in the later months of winter.

Forced rhubarb grown in sheds is more tender than crops grown outdoors and is also ready earlier. Grown in the dark, the rhubarb leaves become an etiolated yellowish-green and the petioles (leaf stalks) are smooth and coloured crimson by anthocyanins. The pickers have to pull the stalks in darkness because light stops the plants’ growth.

Harvesting continues into late March, by which time the rootstock is exhausted — and the pickers may be too.