Garden Rhubarb, Rheum undulatum, The poisonous leaves of Garden Rhubarb are used as a pest spray. Edible stalks in are used in salads, stewed or made into wine. The medicinal root is utilised in the treatment of constipation. Garden Rhubarb is native of central Asia and is adaptable to most good garden soils in a protected, sunny position. Frost resistant but drought tender. A perennial plant, growing to a height of 1m x 3m.