Garden Mastery Tips
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Summer 2009 |
Rhubarb – Poison to Pie
So how did a plant with poisonous leaves and roots become a summertime treat? Blame it on Benjamin Franklin!! Actually, rhubarb has been used as a medicinal plant in China since at least 2700 BC. The roots were used as a purgative or laxative for digestive system problems. The plant was used for medicinal purposes in Asia and Europe for the last five thousand years. The first known rhubarb in America came when Benjamin Franklin sent a box of rhubarb from London to a friend here in 1770. Because the oxalic acid in the leaves and roots make them poisonous, people eating them tended to die, thereby reducing its popularity as food. The stalks of the rhubarb plant contain less oxalic acid, although still there is enough to make them very astringent – mouth puckering in fact! Rhubarb stalks were not used as a food until the 1800s when sugar became more readily available to counter the astringency of the taste. Rhubarb became so popular in pies that it is also known as Pie Plant. The name rhubarb derives from the Roman name for the Volga river (Rha), and the Latin word barbarum, for foreign, since the plant came from territory across the river not controlled by Rome. The word “rhubarb” is also used to describe a fracas or fight. “Rhubarb” is especially used in this context in baseball to describe a fight among the players. This use of the word started with the theater, where a crowd of people is instructed to murmur “rhubarb, rhubarb, rhubarb” to sound menacing and ready to riot.
There are at least 60 species of rhubarb, most commonly used for food being Rheum rhaponticum or Rheum rhabarbarum or hybrids of these. Some of the recommended varieties are Canada Red, Cherry Red, Crimson Red, Ruby, and MacDonald. Most people prefer the varieties with the reddest coloring, although the flavor of the green varieties is the same. Rhubarb is actually a perennial vegetable, although used as a fruit. In 1943 the courts in the United States declared it a fruit in order to standardize its import duties as fruit. It’s tart, astringent taste lends itself to combination with sweeteners, either sugar or sugar substitute, or another sweet fruit such as strawberries or apples. Although most commonly used in a sweet dessert, rhubarb sauces can also be used as a savory enhancement to dishes such as pork, chicken or fish. In Iceland, rhubarb soup is popular.
Rhubarb is grown by many home gardeners, and is available from many nurseries and through catalog sales. It is one of the first garden plants ready to harvest in the spring. Three to six plants produce enough rhubarb for a family of four generously. The plants have large leaves, are perennial, and require space, so planting them at the edge of the garden where they can remain undisturbed for five years is best. Plant in an area with good drainage. Plenty of well rotted manure or compost worked into the soil increases production. Rhubarb, like celery, likes lots of water. Otherwise the stalks become stringy and tough. Fertilize with compost or complete garden fertilizer in early spring, just as growth begins, and again in late June as production winds down. The leaves die back in the fall, and start to grow again in early spring. Plants continue to produce for about four or five years, then must be divided to continue production. Small, tough stalks are a signal that it is time to divide. The best time to divide is in early spring, just as the leaves are emerging. Using a shovel, slice down through the crown (wearing heavy shoes or boots!!) and cut into four to eight pieces, each with at least one strong bud. Re-plant the crown sections 2 inches below the surface of the soil, at least 48 inches apart. Keep them moist and mulched.
Harvesting rhubarb is easy. Wait until the leaves are fully developed, then pull the stalks (which are actually petioles) away from the base of the crown, like pulling a stalk of celery off a bunch. Snap off the stalk at the bottom. Avoid cutting the stems with a knife, as this wound may allow rot to set in. In the plant’s first season, harvest only the biggest stalks, allowing the rest to nourish the root system. Never take more than half the stalks in one year, and stop harvesting by mid-summer to allow the plant to nourish itself for next year. If the plant produces seed stalks, cut them off before the flowers open. Some references say they can be eaten like broccoli, others say to discard them.
Rhubarb recipes abound on the internet. Since rhubarb is low calorie (26 calories per cup), and can be sweetened with sugar substitute or other fruits, it makes a great diet food. It has 10 mg of Vitamin C per cup, and 2 grams of dietary fiber. The Calcium in rhubarb is bound up by the oxalic acid, so it is not a good source of calcium. The easiest use is what we did as children, just dip a stalk into sugar and munch away! Cut stalks into ¼ inch pieces and add as a tangy zest to muffins, cakes and biscuits. Rhubarb sauce is easy, being just cut up pieces of rhubarb boiled with just enough water to cover, with sugar to taste (about ½ to ¾ cup per pound of rhubarb). Cinnamon, nutmeg, lime or lemon juice can be added for variety. Rhubarb can be used to make wine, jam or pie. Here are two recipes to get you started:
Rhubarb Pudding Cake (From Marion Owen’s article referenced below) Arrange 3–4 cups of diced rhubarb on the bottom of a lightly greased 9x13 pan. Sprinkle with ½ to ¾ cup sugar (or sugar substitute). Prepare a batter from a boxed white, yellow lemon or spice cake mix, using one less egg than the recipe calls for. Fold in poppy seeds, raisins or sliced almonds. Pour the batter over the rhubarb. Bake according to the instructions on the box.
Rhubarb Meringue (From Micki Stauffer)
2 Sticks butter or margarine (softened)
2 ¼ cups flour, divided
2 ¼ cups sugar, divided (or sugar substitute)
6 eggs, separated
¼ tsp salt
5 cups chopped rhubarb (about ¼ inch pieces)
2 tsp vanilla
- Crust: Cream butter, add 2 cups flour and 2 T sugar. Slowly blend flour mixture and butter. Pat dough into 9x13 pan, smooth evenly. Bake @350°F for 10 minutes.
- Filling: Beat egg yolks with wire whip. Combine 2 cups of sugar, remaining 4 T flour and salt. Add slowly to egg yolks, combining thoroughly with wire whip. Stir in rhubarb. Pour this mixture over baked crust, spread evenly. Return to 350° oven and bake 45 minutes.
- Meringue: Beat egg whites until soft peaks form. Slowly add 2 T sugar and vanilla. Spread on top of rhubarb mixture. Bake 10 minutes @ 350°F.
Cautions about rhubarb (besides don’t eat the leaves) include using a non-reactive pan for cooking, such as anodized aluminum, stainless steel, Teflon coated aluminum or cast iron. Since rhubarb contains oxalic acid, cooking in reactive pans (aluminum, iron or copper) will result in metal ions reacting with the oxalic acid, turning both the rhubarb and the pan brown. Troublesome pests include the Rhubarb cuculio, a snout beetle that bores into the stalks, crowns and roots of the plant. Cabbage worms can also be a problem, eating holes in the leaves.
Rhubarb can be preserved by freezing. Chop it into ½ inch pieces and spread them on a cookie sheet and place in the freezer. Once frozen, slide them into freezer bags and seal and put back into freezer. Rhubarb will keep for six months in the freezer.
Enjoy!!
References
“Rhubarb: The World’s Favorite Pie Plant” by Marion Owen
“Rhubarb”, Wikipedia
“Rhubarb”, University of Illinois Extension Service
On Food and Cooking; The Science and Lore of the Kitchen by Harold McGee, Simon and Schuster Fireside Edition, 1997
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