Rhubarb is a cool-season, fruit-like vegetable known for its colorful stalks and tart flavor. Its emergence from the ground in late March and early April signals the commencement of spring and opens the growing season gates for home gardeners.
Rhubarb is grown for its hearty stalks only, as its leaves contain the toxin oxalic acid and should not be ingested. Rhubarb is touted for its unique flavor and medicinal benefits as it is high in Vitamin C and rich in Calcium, and it is readily enjoyed in pies, jams, chutney, and other baked goods.
Follow our guide on how to plant and grow rhubarb so that you can enjoy this hardy and reliable perennial favorite for many years to come.
Ideal Soil Composition & pH for Growing Rhubarb
Rhubarb is a hardy plant that can thrive in a variety of soils. However, it is a heavy feeder of soil nutrients and thrives optimally in nutrient-rich, well-draining soil that is loaded with organic matter. You can improve your native soil by mixing a few inches of well-decomposed compost and other organic soil amendments. Mulch well around the plants to help regulate temperature and moisture levels.
If you are uncertain of your soil’s quality, visit your local extension center with a soil sample to test your soil so you can amend it accordingly.
Ideal Rhubarb Growing Conditions
The ideal climate for growing rhubarb are regions where the winter temperatures dip below 40 degrees Fahrenheit and have summer temps that soar above the 75-degree mark. Rhubarb plants enjoy full sun conditions and can tolerate some partial shade.
How to Plant & Grow Rhubarb
Rhubarb is a hardy perennial that can be planted in early fall or in early to mid-spring. Once established, rhubarb is relatively self-sufficient and can keep producing for many years. So, select a spot where the plant will be allowed to flourish and spread while undisturbed. A corner of a garden bed is usually ideal.
When to Plant Rhubarb
- Plant rhubarb crowns in early spring, when the ground becomes workable and the plant’s roots are still dormant.
- Another option is to plant rhubarb in the fall after its dormancy has set in.
How to Plant Rhubarb
- Loosen up the soil area before planting.
- Work well-decomposed compost into the soil before planting.
- Plant rhubarb crowns at a depth of 2 inches and cover with soil.
- Rhubarb plants require plenty of room to spread out. They can spread to up to five or six feet in width for each plant. Plant them four to six feet apart.
The Best Way to Water Rubarb
Plenty of water is required for growing rhubarb. In early spring, nature usually provides what the plant needs from melting snow and spring showers. As the growing season progresses, rhubarb plants need to be watered regularly, especially during the heat of summer. It is essential to provide the plant with enough water for the roots to establish before going to the plant’s winter dormancy period.
Nutrients Needed for Growing Rubarb
There is no doubt about it; rhubarb is a heavy feeder of nutrients. Rhubarb plants produce immense leaves that use the summer months to bolster their rhizomes for subsequent years’ harvests. When fed adequately, rhubarb plants will grow billowing leaves on mature plants.
- When growing rhubarb, there is no need to add fertilizer in the plant’s first year; in fact, direct application of nitrates can cause the demise of plant roots.
- Any fertilization should be done when the ground is still partially frozen.
- After the last frost following planting, apply a small amount of high-nitrogen fertilizer before the ground has thawed, or side-dress the plant with well-decomposed compost and other organic matter. This will feed the soil rather than directly seeking plant roots.
Common Rubarb Growing Problems
Growing rhubarb is rather low-maintenance. This plant is relatively undisturbed by garden pests and disease. Once you know how to plant and grow rhubarb, you’ll find the biggest problem for rhubarb plants is crown rot and root rot.
- Crown and root rot can be avoided by providing rhubarb plants with well-draining soil. Rhubarb plants do not like wet feet. If soil is too soggy, the rhizomes and crown of the plant will rot.
When to Prune Rubarb
Growing rhubarb plants may produce tall flower stalks, which are not at all helpful for a flavorful harvest or next year’s yields. Flowers steal the energy from the plant, which will result in reduced yields in subsequent years. If you happen upon these tall flower stalks shooting up from the middle of the rhubarb plant, cut them off at the base of the plant with your pruning shears as soon as possible.
How to Harvest Rhubarb
- Allow rhubarb plants to get established before harvesting stalks. Refrain from harvesting stalks during the first year of growth.
- Look for stalks that are at least 12 to 18 inches long. Stalks should be thick and robust. If the stalks are thin, do not harvest them. The plant will need its leaves to feed the plant.
- Cut the stalks off the plant at the base.
- Cut the leaves off of the plant stalk and dispose of them.
- Never cut all of the stalks off of your rhubarb plant at harvest time. The plant needs at least two or three leafy stalks to provide food reserves for next year’s harvest. This practice will keep your rhubarb plant going strong for many years to come.
- When the plant dies back at the end of the growing season, remove plant debris and add it to your compost pile.
- Add a layer of well-decomposed compost and organic mulch to the area after the first hard frost. This will feed the plant with enough nutrients for next year’s growth.
Recommended Rhubarb Varieties to Grow
Now that you’re planning on growing rhubarb, try out some different varieties in your garden this year and enjoy varied textures and sweetness. Here are some of our favorites:
- ‘Cherry Red Rhubarb‘ is one of the sweetest of all rhubarb varieties. It produces tender, sweet-tasting stalks that are long and profuse.
- ‘Riverside Giant Rhubarb‘ is a large and cold-hardy plant that produces greenish-red stalks. It is slow to establish itself, however, and can take a couple of years before stalks are harvestable.
- ‘Prince Albert‘ is an heirloom variety that has been prized in gardens for many years. It produces red tart stalks that can be harvested in late April and May.