Photo essay: If you are quiet you can hear it growing...
Forced Yorkshire rhubarb grows in the darkness at the E Oldroyd and Sons farm in Rothwell.
The rhubarb is harvested by candlelight so the remainder of the crop is not disturbed or affected by the light.
Forced rhubarb begins life as cuttings taken from a mature crown two years before harvesting. When strong enough the cuttings are planted in fields to mature, ready for the forcing shed.
After it is harvested, forced rhubarb has a sherbet, tangy flavour and a delicate texture.
Farmers say that you can hear the popping sound of forced rhubarb as it grows in the dark.
Though rhubarb is a vegetable, in 1947 a court in Buffalo, New York, reportedly ruled that it was a fruit because it was eaten as such in the United States.