Growing Rhubarb
GROWING RHUBARB
THE PLANTING SITE
Rhubarb thrives in soil that is well drained with lots of organic matter. It should be grown in a place of full sun. The soil pH should be in the 6.0-6.8 range. The area should be cultivated at least a year prior to planting, being kept free of grass and weeds. Rhubarb plants are excellent to be used for a border or perfect to be placed at the edge of your garden.
SPACING
Space each root crown 2’-3’ between each plant and 4’-6’ between the row, depending on your cultivation or harvesting equipment. A narrow spacing can work if you plan to only mulch between the rows.
PLANTING
New plants are most frequently started by root divisions. Plant them in early spring as soon as you can work the soil. They are an early crop so they will want to grow out quickly. If it is too wet or impossible to plant immediately, store the root crowns in a plastic bag in the refrigerator or a cool, dark place and keep slightly moist. Do not store soaking wet. They will store for several weeks, if kept in cool (34ºF) conditions.
Plant the root cutting 6-8 inches deep. Set the buds so they point upward and cover them with 1 to 1 1/2 inches of soil. Planting too deep can kill them. Shallowly planted crown buds covered lightly with soil and mulched usually grow out very quickly. Tamp the soil down well and water thoroughly. Remember, planting too deep can cause the crowns to rot instead of root!
IRRIGATION
Maintain good moisture, but do not overwater in the first year of establishment. Water during summer stress and dry periods. Maintain mulch around the crown to retain adequate moisture.
MULCHING
Rhubarb plants respond well to lots of composted manure, old hay mulch or straw. Mulching helps control weeds and maintains moisture. It also keeps the plant cooler during hot summer days. Rhubarb prefers a cool weather growing environment. Mulching provides some protection from summer heat and stress. Do not use any fertilizer the first year.
CARING FOR YOUR RHUBARB
Rhubarb is easy to grow and is a wonderful early garden addition to make into pies, tortes, desserts, and sauces. It grows best where winters have at least two months of cold weather and springtime is cool and moist. The leaves are toxic, but the stalks are delicious, having a tart, tangy flavor when cooked.
HARVESTING
Do not harvest any stalks in the first season. The second year after planting, harvest lightly, removing only a few of the largest stalks. By the third year you can expect to be harvesting during early May and June. Some fall harvesting is done sometimes, when plants are very vigorous.
When harvesting, select the largest stalks and grasp them close to the base, giving them a quick pull. They should disconnect cleanly without breaking at the base. Remove the leaf section at the top with a knife, leaving only the stalk part to be used. Always leave some of the smaller stalks to remain on the plant.
When seed stalks appear, snap them off at the base and discard. Discontinue harvest when the stalks become too small.
FERTILIZING/MULCHING
Rhubarb responds well to fertilizer. After the first year use 1/2 cup (4 oz.) of 10-10-10 garden fertilizer around each plant early in the spring. Natural fertilizers, or manure, can also be used with equal success. Lots of irrigation and fertilizer enables the plant to make large, healthy stalks!
RENOVATION
After 5-7 years, divide the plant to maintain strong petiole, or stalk size. Make the divisions in late winter to early spring when the plant is dormant. Take a shovel and cut the old crown into numerous pieces (4 or more usually) and replant each new section again. Part of the old plant can be left in the same spot but you can allow it to regrow again, creating a new set of root clumps.
PESTS
Rhubarb is generally pest-free. Diseases of the plant are rare. Occasionally, they succumb to verticillium wilt, similar to certain strawberries. A symptom is yellow leaves early in the season and the plant remains stunted or dies. There is no cure. Replant in a new area. Crown rot occurs sometimes, and when it does the area is probably too wet or too shady. Avoid planting in such locations.
WEED CONTROL
Rhubarb is very sensitive to herbicides. There are no chemical weed control methods suited for rhubarb, so mulching or manual weeding is necessary.
Rhubarb plantings can produce for many years when they are planted in good locations and assisted with some gardener’s care.
Courtesy of Schlabach's Nursery. For more information, we recommend David Schlabach's book, Backyard Fruit Production, which we have available for purchase.