Rhubarb, genus Rheum, has a long history of medicinal use in Asia. Its use as a food crop appears to be much more recent, with widespread table use beginning in the 19th century. The leaves of the plant are toxic, but the fattened petioles are consumed most commonly in pies and other sweetened desserts, in beverages, and occasionally as a vegetable. Several species of Rheum exist, and modern culinary varieties were likely derived from crosses between some combination of these species. The genus Rheum is not closely related to other vegetable crops; it belongs to the family Polygonaceae, along with buckwheat and many weeds including sorrels and knotweeds.
Rhubarb is a perennial that requires a dormant winter period below 40F to stimulate vigorous spring growth. It grows most vigorously in cool conditions, and growth is suppressed at high temperatures (>90F). For this reason, rhubarb is adapted to Northern latitudes in the U.S. and Canada. Once established, a rhubarb planting can remain productive for 8 to 15 years.
Types and Varieties
Rhubarb varieties are classified as red, green, or speckled (pink). The market generally prefers red over green or speckled.
In New England, the most common variety grown is Macdonald, also known as Macdonald's Canadian Red or Macdonald Crimson. This cultivar has large stalks and a vigorous and upright-growing habit, and is resistant to wilt and root rot. It is probably the most common variety available. It is excellent for pies, canning, and freezing. It can have medium to heavy seed stalk production. At the beginning of the harvest season, late May, the petioles may be a deep red but will lose some or all of their color as the weather warms and as harvest extends through June into early July.
Red types: Crimson (may also be called Crimson Cherry, Crimson Red, or Crimson Wine). This is reportedly the only variety of consequence in Oregon but is reported to do well in New England. It produces brightly colored red stalks with the unique characteristic of being red throughout. Other vigorous red varieties include Valentine and Cherry Red.
Speckled types (pink): Victoria produces large stalks of excellent quality, long, round with smooth ribs. It develops pink speckling on a light green stalk with the pink color being more intense at the bottom of the stalk, fading to a solid green near the top. Victoria is commonly used for forcing. Strawberry is very similar to Victoria, and may be the same variety. German Wine is similar to Victoria but slightly more vigorous and more intense in color, typically with a darker pink speckling on a green stem.
Green types: Riverside Giant is a cold-hardy, vigorous producer with large diameter, long, green stalks.
For more information on varieties, see the Varieties chapter of “The Rhubarb Compendium”