Rhubarb is a relative of buckwheat and has an earthy, sour flavor. Having originated in Western China, Tibet, Mongolia, Siberia and neighboring areas, the traditional role was medicinal—the dried root was a popular remedy for a wide range of illnesses. Its primary function was to induce vomiting, although rhubarb is also a mild astringent.
Beginning in the eighteenth century, rhubarb began to be consumed in foods. Botanically speaking, rhubarb is considered a vegetable, but is most often treated as a fruit. Just like fresh cranberries, rhubarb is almost unbearably tart on its own and needs the sweetness of sugar, honey, or fruit juice added to it to balance out the acidity. Commonly it is stewed with sugar or used in pies and desserts, but it can also be put into savory dishes, or pickled.
Never eat rhubarb leaves, cooked or raw. Eating the leaves can be poisonous because they contain oxalate. This toxin, plus another unknown toxin also found in the leaves, has been reported to cause poisoning when large quantities of raw or cooked leaves are ingested.
Rhubarb, now grown all over the world, is a perennial vegetable that grows as hardy as a weed. It is a very beautiful garden plant, with huge extravagant, lush green leaves and pink or red stalks. If you add rhubarb to your garden, it should be planted at the end of one side of the garden where it will not be disturbed since it may be productive for five years or more. A half-dozen plants will provide enough rhubarb for a family of four.
Harvesting of rhubarb generally begins in mid-June with a second harvest in August. The deeper the red, the more flavorful the stalks are likely to be. Medium-size stalks are generally more tender than large ones, which may be stringy. For storage, first trim and discard the leaves. The freshly harvested stalks can be kept in the refrigerator, unwashed and wrapped tightly in plastic, for up to three weeks.