Rhubarb - growing tips
Rhubarb is a perennial crop, rich in vitamin C. It is grown for its leafstalks, which are used as a substitute for fruit in pies, sauces, and jams. The wide, upper portion of the leaf contains toxic substances and must not be eaten. A few hills (or clumps) of rhubarb can usually supply all that a family needs. As with other perennial crops, it should be planted to the side of the garden, or entirely separate from it, where it will not be disturbed by the tilling necessary for annual crops.
As soon as the soil can be worked in the spring, obtain pieces of a crown from a friend or buy roots from a nursery. MacDonald, Canada Red, Victoria and Valentine are good varieties for New England. Rhubarb can also be planted in the fall in Massachusetts.
Select a site with full sun, deep soil and good drainage, allowing about 9 square feet per plant. Because rhubarb needs a steady supply of moisture during its growing season, the planting site must be very well prepared: Dig a hole about 2 feet across and 12 to 18 inches deep for each plant, pilling up the topsoil and discarding any subsoil. Add a 6 inch layer or organic matter (compost, composted manure or peat moss) to the bottom of the holes. Mix the topsoil with an equal amount of organic matter, 1 pound of 10-10-10 fertilizer, and if necessary, line to raise the soil pH to between 5.5 and 7.0. Return part of the topsoil mix to the hole. Set the crown in so that its top is 3 to 4 inches beneath the soil surface. Firm the soil around the crown, and then fill the hole with the remaining mix.
Do not harvest any leafstalks for the first two years after planting, but do remove and discard the seed stalks as they appear to prevent the plants from spending their energy forming seeds.
Begin harvesting in the third spring. Pick the stalks by pulling and not by cutting. Grasp a stalk near its base and pull it slightly to one side in the direction it grows. It will separate readily from the crown. Harvest only those stalks that are greater than one inch in diameter, and harvest for only 4 weeks. In future years the harvest can be continued for 8 to 10 weeks.
Alternatively, a continuous harvest throughout summer and fall is possible on established plants. Pick a few stalks ( a pie’s worth or so) every couple of weeks. The plant will not be severely stressed by foliage loss and the gardener will not be stressed by having to preserve large quantities of sauce or jam. Watch carefully for the appearance of seed stalks, and remove them promptly. Otherwise, the leafstalks will become tough.
Every fall spread a layer of organic matter several inches deep over each plant. Early in the spring, before growth starts, work about a pound of 10-10-10 fertilizer into the soil and around each plant, being careful not to get close enough to the crown to injure it.
A rhubarb bed will continue to produce for many years. If the plants begin to produce smaller stems after a number of years, life, divide and reset the plants in the late fall or early spring to restore vigorous growth.