Authored by Jennifer Kret, UMN Public Health Nutrition
June is already here, and that’s right, it is rhubarb season! As you may know, rhubarb is often treated as a fruit, commonly found in tarts, compotes, or a slice of Garrison Keillor’s favorite, Bebop-a-Reebop Rhubarb Pie. Although, rhubarb is truly a vegetable. It belongs to a group of herbaceous perennials in the species, Rheum. There are various types of rhubarb grown throughout the world, but the red stalks of Rheum rhubarbarum are probably the most recognizable species and most commonly grown in northern regions of the United States.
The large leaves and bright stalks make rhubarb a distinctive and ornamental plant for a home garden. Growing rhubarb from seeds may take a long time for plants to become established, so it is best to get started by propagating rhubarb or purchasing a rhubarb plant. Rhubarb thrives in colder climates, originating in Western China, Tibet, Mongolia, and Siberia. This versatile veggie is not only winter hardy and able to tolerate temperatures as low as -20 F, but it can withstand drought conditions, to boot. Once planted, a rhubarb plant can be productive for many years.
Rhubarb has been widely used in Chinese medicine and folk healing for centuries for positive and balancing effects on the digestive system. It was not until the late 18th Century that rhubarb was used for culinary purposes in Europe and America. The high acidity of this vegetable gives it its sour, earthy flavor, tart like a cranberry, and it is the reason rhubarb is often balanced with the sweetness of sugar, honey, or fruit juice. However, rhubarb has many culinary uses beyond the traditional sweet desserts, pastries and sauces. It can accompany savory meat entrees or be used in chutney, salsa as well as soups (click here for more recipe ideas).
Nutritionally speaking, rhubarb stalks are a fair source of fiber, vitamin A, and vitamin C. Rhubarb stalks also contain a moderate amount of potassium and calcium. Yet, as in spinach, sweet potatoes, and beans, the calcium in rhubarb is combined with oxalic acid. When compared with calcium absorption from milk, this form of calcium is not as easily absorbed by the body. Furthermore, while oxalic acid is present in low amounts in the stalks, it is highly concentrated in the leaves of rhubarb plants. The amount of oxalic acid in rhubarb leaves is enough to cause a poisoning effect when ingested, thus it is never advisable to eat them, cooked or raw.
At the market or fresh from the field, choose stalks of rhubarb that are flat and not limp. Soft or mushy appearing stems should be avoided because the oxalic acid in the leaves could have migrated into the stalks as a result of cold injury. Size is not an indicator of tenderness, but deep red stalks can be sweeter and richer. Remember, if you harvest rhubarb from your home garden, cut off the leaves! Rinse and trim the stocks. Rhubarb can then be kept in the refrigerator for one week or possibly longer. Simply wrap the rhubarb in plastic and store it in the coldest part of the refrigerator. Cooked and raw rhubarb freeze well.
Whether you decide to try your Grandmother’s rhubarb pie recipe or exercise your culinary creativity, enjoy some fresh, tart rhubarb this summer!