Plant of the Week: Rhubarb
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Plant of the Week
Latin: Rheum rhabarbarum
Free Pie Wednesday is a big hit at our house and the one evening we are likely to eat out. On the list of free pies for this particular restaurant, is its toothsome strawberry rhubarb pie, especially good with a dollop of ice cream on top. As a kid, I never much liked rhubarb pies, but now that I’m older I know it has a tart but tasty flavor and a fascinating history.
The name rhubarb probably comes from a contraction of a Greek descriptive term used as a shorthand describing where the plant came from; “Rha,” an old name for the Volga River of Eastern Russia, and “barbarous,” or foreign. Rhubarb has a long history of significance to mankind but mostly as a medicinal plant, not in the making of pies. To further complicate matters, several of the more than 60 species that have been described all share the same common name.
Rheum rhabarbatum and R. rhaponticum, or their hybrids, are the common rhubarbs grown in gardens, also called pie plant in the United States. They are perennial herbs of the knotweed family native to Central Asia, southern Russia and Siberia, Mongolia and northern China. The Chinese used rhubarb for at least 2500 years, but they primarily collected roots of R. palmatum for use in medicine. During the 15th through the 18th century the value of dried rhubarb root, which was primarily used as a laxative, was several times more expensive than that of cinnamon, opium and saffron.
The rhubarb of gardens grows to 2 feet tall and 4 feet wide with large, undulate shaped leaves that emerge from a crown on stout, often red-tinted petioles. Well established plants send up flower stalks that may reach 5 feet in height, with dense clusters of small white, pink or red flowers. Flowering is not desirable in rhubarb production so bloom stalks are typically broken off as soon as they appear.
The first introductions of rhubarb seeds into Europe were for planting in apothecary gardens in the early 17th century. It was not until sugar became relatively cheap and widely available a century later did northern European gardeners figure out that the tangy taste, due to 2.5 percent oxalic acid concentration, of rhubarb stalks (actually petioles) were good for use in pies. In part, it became popular because it was the first fresh produce of the year that could be made into pies, usually 6 to 8 weeks before the first fruit crops came into bearing.
Rhubarb, and possibly rhubarb pie, was introduced to the United States due to a 30-year correspondence between Philadelphia’s native plant hunter John Bartram and his English patron Peter Collinson. In a letter dated Sept. 22, 1739, Collinson checks in with Bartram about the two species of rhubarb seeds he had sent Bartram a few years earlier. In the letter, he gives a recipe for making rhubarb tarts and tells Bartram: “Eats best cold, it is much admired here, and has none of the effects that the Roots have.” In 1770, Benjamin Franklin, while traveling in France, forwarded seed of R. palmatum to his friend Bartram that had been collected “near the Chinese wall.”
Rhubarb is native in the northern latitudes so is uncomfortable in the swelter of the South. It is hardy from zones 3 in the north to zone 7 in the south, or possibly a bit further south if a perfect location can be found. In Arkansas, the ideal rhubarb site will be either a north facing slope or a site that has morning sun and afternoon shade such as the east side of the house. It should have a rich, highly organic soil with good drainage and abundant water during the growing season. Avoid high clay content soils. Leaves harvested in the early part of the growing season are the largest and of the highest quality.
By: Gerald Klingaman, retired
Retired Extension Horticulturist - Ornamentals
Extension News - January 18, 2013
The University of Arkansas Division of Agriculture does not maintain lists of retail outlets where these plants can be purchased. Please check your local nursery or other retail outlets to ask about the availability of these plants for your growing area.