Rhubarb is the first "fruit" of the season - used as a fruit, but grows like a vegetable. With huge leaves on long red to green petioles it can also make a dramatic statement in the garden. This oldfashioined perennial is very easy to grow, coming back bigger year after year with little care. To learn more about rhubarb, read this article...
Rhubarb is a hardy perennial in the buckwheat family (Polygonaceae). The ancient Chinese used it as a medicinal herb over 5,000 years ago. Native to southern Siberia, it got its name from the Russians who grew it along the Rha river (now the Volga). For centuries it was traded alongside tea as a cure for stomach aches and fevers. The English were the first to eat rhubarb, beginning in the 17th century, but unfortunately chose to begin with the leaves that look like chard. The leaves, however, contain a toxic amount of oxalic acid and are poisonous. The ensuing cramps, nausea and sometimes death from ingestion suppressed interest in the plant for about two hundred years. But by the late 18th century Europeans had discovered that the tart stalks were the part to eat – perfect for "tarts" giving rise to the nickname "pieplant." It was brought to the Americas by settlers before 1800.
There are many species of plants called rhubarb (and not all are botanically related to the edible type). The edible garden rhubarb, Rheum rhaponticum, is also refered to as Rheum x hybridum, Rheum rhabarbarum, or Rheum x cultorum. It is a perennial plant that grows 2 to 4 feet tall with large, smooth, heart-shaped leaves. The plant grows from large, fleshy reddish-brown rhizomes with yellow interiors. The leaves emerge from crown buds when temperatures begin to exceed 40ºF in early spring. The thick, succulent red or green leafstalks (petioles) grow up to 18 inches long and 1-2 inches in diameter, with leaves up to a foot or more in width. Small white flowers grow on a stalk that elongates from the crown. The plant dies back to the ground each winter.
Rhubarb varieties are classified as red, green, or speckled (pink). Most people prefer the red stalked types, although the green ones are generally more productive. Red stemmed types are not necessarily sweeter because color and sweetness are not always related. In many cases, the same variety has acquired different names in different areas, as the plants get moved around, or with color variations, particularly for types grown from seed. Although you may wish to purchase specific varieties, don’t overlook acquiring equally productive and delicious, un-named "heirloom" plants from friends’ backyards.
Some commonly recommended varieties include:
- ‘Canada Red’ often produces shorter, more slender stalks than other varieties, but is tender and very sweet with good red color. It tends to produce few seed stalks.
- ‘Cherry Red’ (also known as ‘Cherry’ or ‘Early Cherry’) has long, thick stalks that are a rich red inside and out. This vigorous producer is juicy, tender and sweet.
- ‘Crimson Red’ (also called ‘Crimson’, ‘Crimson Cherry’, or ‘Crimson Wine’) produces tall, plump, brightly colored red stalks.
- ‘MacDonald’ produces well and has tender skin on the brilliant red stalks.
- ‘Valentine’ has broad, deep red stalks that retain a good rosy color when cooked. It is much less acid than green stalked and other red varieties, and produces few or no seed stalks.
- ‘Victoria’ is a speckled type that produces medium-sized stalks of excellent quality and good flavor. Although there is some variation in stalk color depending on the strain, in general the light green stalks develop pink speckling, especially at the bottom of the stalk.
Rhubarb is very easy to grow. The plants like rich, well-drained soil high in organic matter, but are somewhat adaptable. Lighter soils will produce an earlier crop but require more irrigation and fertilization. Because this perennial will remain in the ground for several years, choose a site in full sun where it can remain undisturbed. Planting on raised beds for good drainage helps prevent crown rot. Prepare the planting site in the fall by eliminating perennial weeds and working in manure, compost or other organic matter. Incorporate fertilizer just before planting in the spring.
Plant the purchased crown pieces or divisions from other plantings about 3 feet apart. Set the pieces so the buds are about 2 inches below the soil surface. Don’t harvest any stalks the first year. Wait until the second or third year so the roots can establish themselves.
Fertilize established plants in the spring after growth starts and again in the summer after harvest. Maintain adequate soil moisture after the harvest season and remove flower stalks when they first appear to keep the leaves growing strongly. Keep grass and other competitors away from rhubarb. You may want to mulch in winter (after the ground freezes) to avoid heaving. Divide and reset plants about every fourth or fifth year to keep the plants vigorous.
Although rhubarb can be grown from seed, this is not recommended. Instead, grow from divisions that grow up from the parent plant. Buy divisions or divide your own in spring, about 4 to 6 weeks before the average date of last frost. When replanting divided plants, be sure the crowns are free of disease.
Use a sharp spade or shovel to cut up the crown into pieces, with at least one strong bud for each piece. Instead of digging up the entire plant to divide it, you can just leave a portion with 3 to 4 buds undisturbed in the old location, and remove the remainder.
Well-maintained plants have few pests. Slugs may be a problem in moist areas, and crown rot may affect old clumps. Avoid crown rot by dividing clumps before they get too large. Leaf spots generally do not affect yield.
Harvest & Storage
Rhubarb is most tender and flavorful in spring and early summer, but can be used throughout the season. Select firm, crisp stalks when they are 8 to 15 inches long. To harvest, twist off the leaf stalk at the soil line and cut off the leaf.
Do not harvest more than a third of the leaves in any year to keep the plant going strong (and don’t pull any leaves during the first year of growth). On young plants, pick stalks only in the spring and allow them grow unpicked all summer or growth will be delayed the following spring. You can harvest sparingly on vigorous, well-established plants throughout the summer. Any leaves remaining at the end of the season can be pulled just before the first fall frost.
Store fresh rhubarb stalks unwashed in the refrigerator for up to two weeks. Rhubarb can also be sliced and frozen, with or without sugar. It will keep it the freezer for up to 6 months.
Rhubarb is typically used for jam, simmered into a sauce, or in pies or other desserts, but it also works well as an accompaniment to savory foods. It also blends well with other fruits in preserves and baked goods. Rhubarb is tart and needs to have sugar added, but don’t overdo it!
One of my favorite ways to use rhubarb comes from The California Heritage Cookbook by the Junior League of Pasadena (Doubleday, NY) in a cake that is reminiscent of cherry cobbler.
Fresh Rhubarb Cake
½ cup butter, softened
1½ cups brown sugar, packed
1 tsp vanilla extract
2 cups flour
¼ tsp salt
1 tsp baking soda
1 Tbsp fresh lemon juice
1 cup milk
2 cups coarsely chopped fresh rhubarb
½ cup pecans or walnuts, chopped
½ cup granulated sugar
1 tsp ground cinnamon
In a large mixing bowl cream the butter until it is light. Add the brown sugar slowly, continuing to cream, until the mixture is well blended and fluffy. Beat the egg and vanilla into the creamed mixture until blended.
In another bowl sift together the flour, salt and baking soda twice. Combine the lemon juice and milk, and add it alternately with the flour mixture to the creamed mixture, beginning and ending with the dry ingredients. Beat, after each addition, just enough to blend. Gently fold the chopped rhubarb into the batter, stirring just enough to distribute. Pour the batter into a greased and floured 9 x 13 x 2 inch pan, spreading evenly.
In a small bowl blend together the nuts, granulated sugar and cinnamon and sprinkle evenly over the top of the batter. Bake in a preheated 350ºF oven for 45-50 minutes or until a toothpick inserted in the center comes out clean. Cool the cake in the pan at least 30 minutes, cut in squares, and serve. It’s good plain (like a coffecake), topped with whipped cream or served with ice cream.
- Growing Rhubarb in the Home Garden – Ohio State University Extension Fact Sheet HYG-1631-04
- The Rhubarb Compendium – more info on rhubarb than you can even imagine
– Susan Mahr, University of Wisconsin - Madison