Once established, growing rhubarb is practically hands-free. Some growers, in fact, report that established rhubarb is more difficult to kill off than it is to grow, much like an infectious weed. As such, the best tips for growing rhubarb primarily apply to establishing the perennial plant in a new location. Tips to increase success include proper soil preparation and fertilization, choosing a good seed supplier, the proper application of mulch to deter weeds, and choosing a spot in a mostly sunny location.
Successfully growing rhubarb begins with either good seeds or good crowns. Seed suppliers vary in terms of the quality and germination rates for the various seeds sold. Pick a reputable nursery supplier based on recommendations from other gardeners, gardening publications, and adherence to any preferred seed procurement methods. While few studies indicate heirloom or organic seeds have a higher rate of germination, poor quality or old seeds can affect the success rates for growing rhubarb.
Crowns, the divided sections of established plants, offer a far greater success rate than seeds. Most nurseries and plant suppliers offer crowns for growing rhubarb, rather than seeds. Whether using seeds or crowns, planting is best when done during dormancy in early spring or late fall. It is best to space plants to allow for two square feet or more per mature plant. Like many common vegetable garden choices, rhubarb enjoys full sun, in addition to ample space for leaves to spread.
Growing rhubarb is an excellent choice for novice gardeners, owing to the plant's hardiness and versatility in a variety of soils. Although rhubarb will grow in most any soil, it does prefer well-drained soil with a pH between six and seven. Organic matter, such as compost or worm castings, ensure the soil is well fertilized for new plantings. To keep plants healthy, cast compost or similar fertilizers with a high potassium and phosphorus content around the plants. Experienced growers and gardening experts typically recommend casting fertilizer during the summer months, after plants have established.
In addition to using quality seeds or crowns and preparing soil with fertilizer, growing rhubarb is easiest when weeds are kept to a minimum. Perennial weeds pose the most threat to young rhubarb plants. Using a quality mulch not only deters weeds by suffocating unwanted plants but also helps the ground retain valuable moisture.
As flowers appear, remove the stalks to encourage better leaf growth and heartier fruit production. When harvesting, remember that rhubarb leaves are toxic to humans and some animals, so only use the fruity stalks. Leave tops will die off during the winter months, but the roots remain and will regrow in spring, provided good fertilizer is used.