Rhubarb

Rhubarb (Rheum spp.) is a perennial flowering plant in the buckwheat family Polygonaceae, grown primarily for its thick, tart stalks. The plant bears large, crinkled leaves that are poisonous due to oxalic acid and should not be consumed. Stems vary in color from green to red or pink, and are eaten when cooked to soften their sharp flavor.

Rhubarb is hardy in cool, temperate regions and prefers well-drained, fertile soil, full sun to partial shade, and regular moisture. It is typically propagated by divisions of the crown or rooted rhizomes and can live many years. For healthy yields, avoid overharvesting in the first year and allow the plant to establish itself. Harvest begins in spring when stalks reach usable size. Cut or pull stalks from the base, leaving plenty of foliage to renew growth.

In cooking, only the stalks are used. They are usually sweetened and cooked into pies, sauces, compotes, jams, or crumbles; they are commonly paired with strawberries or other berries. Leaves contain oxalic acid and are discarded. Fresh stalks can be stored in the refrigerator for up to a week, and they may be blanched and frozen for long-term storage.

Rhubarb varieties are bred for stalk color, size, and flavor, with many cultivars available. Nutritionally, rhubarb stalks provide fiber and small amounts of vitamins C and K, with minimal calories, but they also contain oxalic acid that can affect kidney function in susceptible individuals if consumed in excess. Pests and diseases include crown rot, powdery mildew, and rhubarb curculio in some regions.