Rhubarb Plants - Planting and Care Guide
Purchase started rhubarb plants if you can find them, crowns, or divisions (clumps of roots, each clump with one or more "eyes," or buds). Rhubarb is rarely planted from seed. Keep the crowns in a cool place until you have time to plant them.
Plant rhubarb in early spring, as soon as you can work the ground. In mild climates, plant in the fall. Grow rhubarb where you won't need to disturb it for a couple of decades and where the soil is fertile and well drained. Rhubarb planted in heavy clay can rot before it sprouts. Choose a site in full sun for the most prolific harvests (but rhubarb will grow in partial shade). It will tolerate a pH as low as 5.3, but its ideal range is 6.0 to 6.8. Prepare the planting bed well (remember, this is a permanent bed; you won't be tilling it and replenishing the nutrients every year). Dig deeply and add plenty of organic matter.
Dig a trench at least two feet across and just as deep if you're planting more than one crown. For a single plant, dig a hole at least two feet in diameter and the same depth. Then partially refill the trench or hole with a 50-50 mixture of soil and compost or well-rotted manure.
Allow at least three feet between plants. For each plant, make a mound of soil, then set in the crown and spread the roots down over the sides of the mound. Add the remainder of the soil so that the buds are one to two inches below the surface, and lightly firm it. (Set crowns a little deeper in sandy soil.)
Mulch heavily with grass clippings, shredded leaves or compost as soon as the first shoots emerge, and make sure new plants get at least an inch of water a week.
Remove seed stalks as soon as they appear; once the plant starts producing them it stops producing leaf stalks. (Seed stalks will start forming later in the summer; they're tall, thick and round - very different in appearance from the edible leaf stalks.)
Top-dress the bed with compost or well-rotted manure in late autumn, after the plants have died back. Top-dress again in the spring, and every fall and spring thereafter.
Refrain from harvesting any rhubarb the first year, but do keep the flower stalks clipped off. The second year, in early spring, harvest a few leaf stalks (also known as petioles) that reach the thickness of a finger, but leave most of them on the plant; they're essential for good root development.
Harvest as many finger-sized petioles as you want from the third year on.