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Tips for growing rhubarb

Rhubarb should be planted in the early spring.
Rhubarb should be planted in the early spring. TNS photo

As I am writing this column the weather is certainly not gardening weather, with ice continuing to build up on the white pine trees outside the windows. So I thought maybe I could brighten your day by discussing one of the earliest producing vegetables in the garden — rhubarb. I remember how my mother enjoyed rhubarb sauce and I certainly enjoyed her strawberry/ rhubarb pies. For the home gardener, rhubarb can be source of enjoyment year after year, once the plants are established.

Rhubarb is a perennial crop that is grown for its large, thick petioles or leafstalks. Rhubarb’s water content is among the highest of all common vegetable crops. Rhubarb contains few calories, so it may be useful in low caloric diets. Nutritionally, rhubarb is a poor source of vitamins or minerals; however, its unique flavor and texture — as well as its early spring production — make it a welcome addition to the diet.

Rhubarb grows well on many soil types; however it thrives in a rich, well-drained loam soil. A good idea before planting rhubarb is to incorporate 50-60 pounds of barnyard manure or similar organic material per 100 square feet of garden area. Also remember that since rhubarb is a perennial it should be located to the side of the garden or in an area not disturbed by yearly tilling.

Well before thinking of planting rhubarb, use 8 to 10 pounds of a 5-10-5 (or equivalent) fertilizer per 1,000 square feet of garden and incorporate it into the garden plot. Rhubarb should be planted in the early spring; about the time you plant your potatoes — March/April. Plant in a shallow trench so each bud is about  1/2 to 1 inch below the soil surface. Plants should be 2 to 3 feet apart in the row and if more than one row is planted, 4 to 5 feet between rows. Fill the trench to cover the crowns and firm the soil around the crowns.

Once the plants are established, fertilize each year with 4 to 5 pounds of 5-10-5 (or equivalent) per 1,000 square feet each spring before growth starts, which is usually about March. In late June add about 2 to 3 pounds of ammonium nitrate per 1,000 square feet. Then do not fertilize until the following March. You may, however, apply some strawy manure in early winter if you desire.

Remove the seedstalks from rhubarb plants as soon as they form so that plant foods produced will be stored in the crowns for next year’s production.

Do not harvest any leafstems the year the plants are set. The second year harvest only a few stems in early spring. Full harvest can be made the third year and can last approximately 8 weeks beginning as soon as the stalks are large enough to use. Use only the leafstalk (petiole) as food, since rhubarb leaves contain oxalic acid that may cause lesions in the mouth if eaten. Never eat them. After harvest, rhubarb stalks should be stored in the vegetable storage area of the refrigerator and kept moist until used.

Divide and reset the rhubarb plants every seven or eight years to minimize the production of slender stalks. When dividing plants, be sure each piece contains some large buds of the original crown as well as the large, thick roots.

You can then enjoy harvesting your own rhubarb and making rhubarb sauce and rhubarb and strawberry pie. Maybe you will win a prize for the best pie at the county fair.

Bill Lamont is a professor emeritus in the department of plant science at Penn State and can be reached by e-mail at wlamont@psu.edu.