Origin
Although Rhubarb has been known in China as a medicinal plant for more than 4500 years, the exact origin is not known. Rhubarb is most likely indigenous to south-eastern Russia or Siberia.
Uses
Rhubarb is used as a cooked vegetable and in pies and sauces.
Cultivation
Usually thought of as a temperate-climate plant only, Rhubarb can be grown as an annual in sub-tropical and tropical climates that have a cool season. In temperate climates, Rhubarb is propagated by division of rootstocks from 2- to 3-year old plants, but in warmer climates it can be grown as an annual from seed. Plant seeds in nursery pots about 0.5 cm (0.25 in) deep. Transplant when plants reach about 7-10 cm (3-4 in) in height. Plant densely to slow flower formation. Plants rarely form flowers at high temperatures and short day-length, but any flower heads that do develop should be removed (unless you are trying to save seed). Rhubarb plants will tolerate a wide range of pH. For best production, the soil should be a well-drained loam with a high content of organic matter. Rhubarb is fairly drought tolerant; be careful not to over water it as it can get root-rot if the ground is too wet. Rhubarb can do well in temperatures ranging from 5o-25o C (40o-77o F). Rhubarb plants grown at high temperatures will have fewer stems with the intense red color we are used to, but tasting a pie grown from subtropical Rhubarb made us overlook that quickly! We have had good luck at ECHO with Rhubarb by planting seed in August and harvesting in March-May. The variety Victoria is especially productive.
Harvesting and Seed Production
Harvest stalks as they mature. They should be cooled rapidly to prevent wilting. Seed production usually occurs only at higher altitudes. The tall blooms can be dried on the plant and threshed before the tiny seeds are shed. Seeds generally have a short viability. Please note: you may be able to order this seed in quantity from the Park Seed Co., Cokesbury Rd., Greenwood, SC 29647, USA.
Pests and Diseases
Rhubarb is subject to fungal attack from species of Phytophthora, Pythium, Phizoctonia, and Botrytis. Common pests include nematodes, the potato stem borer, and the rhubarb cucurlio.
Cooking and Nutrition
Rhubarb is processed by cooking, canning, and freezing. Its acid taste is due to oxalic acid and can be softened with a little sugar. Rhubarb contains fair amounts of pro-vitamin A and vitamin C. Rhubarb leaves are poisonous; people have died using them as a vegetable green. Eat only the stalks!