Why: Rhubarb (Rheum rhabarbarum) is a species of plant in the buckwheat family (Polygonaceae). They are herbaceous perennials growing from short, thick rhizomes. They have large leaves that are somewhat triangular, with long fleshy petioles. The petioles (stems) are a tart, crisp vegetable which uncooked is similar in texture to celery. There is really only one reason to grow it and that reason is pie.
Rhubarb is an old world plant, growing wild along the Volga River in Asia. It has been used for medicinal purposes for thousands of years (it is a mild laxative). It was traded along the Silk Road in the 1400s along with such things as cinnamon, opium and saffron. It came into use as a food in England in the 1600s, when sugar became readily available for cooking.
When the western United States was being settled this plant was known as the pie plant. Laura Ingalls Wilder, for instance, refers to the pie plant in her novella "The First Four Years." This hardy plant was carried by settlers as they traveled west so they could cultivate it when they arrived at their new home. Its thick, reddish stems are a sweet and sour delight when cooked with sugar. They make a delectable pie filling, or preserves. Frequently people combine the stems with strawberries to make a combined pie filling.
How: Rhubarb can be transplanted (either from a friend who is dividing a plant, or a purchased plant) as soon as the danger of frost is over. It takes a few years to really be productive and you might want to consider planting two or three plants if you are impatient. It should be planted in its own space with no other plants around; it does not like competition in the garden. However, this need not be a very large space, the plant will grow to about 4 feet wide. It should be a sunny location with well-drained soil. Add organic material if your soil is less than ideal. Water the plant regularly but do not overwater: Rhubarb does not like wet roots. If your soil is a heavy clay you will probably need to amend significantly to be successful. If this is the case consider building a raised bed for these plants. The raw leaves are mildly toxic because they contain oxalic acid. However, the deer in my yard do eat the foliage. A piece of deer netting will keep them off the plant.
Rhubarb, once, established, is a heavy feeder. It needs a lot of nitrogen to grow nice husky stems. The year you plant it you should not harvest any stalks. Allow the plant to grow with regular fertilizer applications. In the fall, you will remove the foliage and stems after it freezes and mulch the plant with a 1-inch application of composted manure.
Unlike many other food plants, you do want to encourage foliage growth on this plant, so nitrogen can be applied fairly liberally. If your plant bolts (sends up a flowering stalk), prune the flower off immediately. The goal here is to maximize photosynthesis in the summer months so that a lot of energy is stored in the roots for the next year's growth. Since you are not using any flowers or fruit, only the stem, seed production is not desirable
The second year you can harvest stalks for cooking or baking. You can harvest as soon as the plant is large enough for the stalks to be useful. Remove the stalks with a twisting pull, do not break or cut them. Remove the leaves and just use the stems. Remove up to one third of the stalks at one time.
The stalks can be harvested up until July 4, after that allow the plant to grow until the winter freeze. It will take a couple of years for the plant to develop to full size. The plant should be divided when the stalks become slender and the center of the plant becomes nonproductive.
This will probably be about every eight years.
When: Start your plant in spring or summer, the sooner the better.
What's needed: Rhubarb. Several hybrids are available in our region, Canada Red and Strawberry are two examples. Different cultivars may be more or less red in color. Stem color is not related to suitability for culinary use. However some consumers prefer the redder varieties.
A garden space of about 4 feet by 4 feet for each plant. Fertilizer and organic soil amendments.
When you have questions, call the Master Gardener Volunteer Help Desk at Colorado 520-7684 or emailing CSUmg2@elpasoco.com. Volunteers are available to help you Monday through Friday from 9:00 to noon.