Grow rhubarb from root divisions, called crowns, rather than from seed, which can produce plants that are not true to type. Three to six plants are plenty for most households.
Once plants sprout, apply mulch to retain soil moisture and smother weeds. Renew mulch when the foliage dies down in fall to protect roots from extremely hard freezes. Provide enough water to keep roots from drying out, even when they’re dormant. Side dress with compost in midsummer and again in fall. Remove flower stalks before they bloom to encourage leaf-stalk production. After several years, when plants become crowded and the leaf stalks are thin, dig up the roots in spring just as they sprout. Divide so that each crown has 1 to 3 eyes (buds); replant.
Rhubarb is usually pest free. Occasionally it’s attacked by European corn borers and cabbage worms. A more likely pest is rhubarb curculio, a ¾-inch-long, rust-colored beetle that you can easily control by hand picking. To destroy its eggs, remove and destroy any nearby wild dock in July.
In spring when the leaves are fully developed, twist and pull stalks from the crowns. Don’t harvest any the first year, though, and take only those that are at least 1 inch thick the second year. By the third year, you can harvest for 1 to 2 months. After the third year, pick all you can eat.