Rhubarb stalks sprout from the soil early in the growing season, heralding the arrival of spring in the garden.
In pies and jams, the acidic flavor of the tart, with its vivid stems and flavor, must usually be tamed with sugar or mixed with sweet strawberries.
Rhubarb’s sculptural charm comes from its blocky stalks and large leaves.
Unfortunately, while the texture of the leaves is appealing, you cannot eat them. As pretty as they are, they also contain high levels of oxalic acid, which isn’t edible.
Learn how to grow rhubarb and get expert advice on how to get the most out of your rhubarb harvest this season.
Why should you grow rhubarb?
Rhubarb is a long-living perennial which is prized for its super-tart, succulent stalks. It’s usually one of the first spring crops you can harvest from the garden, and it’s an excellent occasion to bake a delicious rhubarb pie.
Rhubarb is also one of the simplest vegetables to grow and a mainstay of North American culture.
When to plant rhubarb
You can grow your rhubarb from seeds, but it takes a long time to grow and can produce plants that aren’t true to the original variety. Planting rhubarb crowns, which are parts of a divided rhubarb plant, is much easier.
Late autumn to early winter is the best time to plant rhubarb crowns. However, November or December is also the ideal time for planting this vegetable.
Container or raised bed?
If you’re going to grow rhubarb in the garden naturally, make sure you purchase your plants from a reliable source to ensure they’re disease-free. Then, prepare a garden bed and dig holes a little larger than the rhubarb crowns.
You can plant the crowns so that the plant’s tip is about 1 inch below the soil’s surface. Then, to ensure that the surrounding soil has no remaining air pockets, pack the soil firmly around the roots.
Soak the soil well around the plant to help your rhubarb establish healthy growth. Spread compost mulch around the plant, but not directly above the developing tip, which will emerge in about four weeks.
You can plant rhubarb directly in your garden or learn how to grow rhubarb in a container or raised beds and decide which method is best.
Although planting rhubarb in containers is not the best method for growing rhubarb, there are a few strategies to make this choice a success.
Learning how to grow rhubarb in containers is a great practice for urban farming or when you don’t have enough yard space – but you should grow rhubarb to make your own pie!
Because rhubarb has a vast root system, you’ll need a patio pot that can hold at least 1.5 cubic feet or 10 gallons of soil. There are always plenty of large decorative pots available at your local gardening center.
Remember that the larger the pot, the more dirt you’ll need. Nevertheless, your rhubarb will have additional insulation in the winter if you choose a large container to grow this vegetable.
Rhubarb prefers well-drained soil, so it will not thrive in wet ground.
If the garden soil is soggy, you should consider growing rhubarb in raised beds. Allow four weeks before planting to dig in lots of organic materials and allow it to settle.
Remember not to relocate the plant while it establishes itself, so you’ll want to add as much nutrient-rich organic matter as possible to keep it going for as long as possible.
You can buy soil enrichers such as organic nutrient-rich compost to improve the quality of the soil.
After allowing the soil mixture in the raised bed to settle, plant your rhubarb as indicated earlier.
Soil to use
How to grow rhubarb best is in well-drained, rich soil that has an abundance of organic matter. In addition, organic matter, such as compost, can help to aerate dense soils.
The organic matter in the soil mixture helps with drainage and minimizes the likelihood of root rot.
Before planting, till the ground deeply (12 to 15 inches) and liberally apply compost. Always use a sterile fertilizer to prevent diseases from forming on the rhubarb, especially if using homemade compost or manure.
How often to water?
During dry times, water rhubarb plants to keep their foliage fresh all summer. Plants with healthy roots can store vast amounts of food, resulting in a good yield the following year.
A deep soak every 7 to 10 days during dry weather should suffice. Mulching with bark or compost on an annual basis enhances soil composition and drainage.
It also aids in water conservation and weed control. To avoid root damage when using a hoe to control weeds, dig the soil shallowly.
Rhubarb plants generate flower-like stalks. You should remove these as soon as possible because the flower and seed formation diminish plant vigor.
Rhubarb produces flower stalks when the soil is infertile, during times of excessive heat or cold, drought, or long days that expose plants to too much light.
Older plants tend to blossom more than those that are younger. After 8 to 10 years, rhubarb crowns are frequently overcrowded. When this happens, the plant sprouts a lot of little shoots, which reduces the yield.
The solution to this problem is to separate the nodes from the crown. Wait two years after splitting the plant before harvesting again.
Early in spring, when the soil is still soft and easy to work, divide the crown of a healthy plant. Dig a deep hole around the rhubarb cluster and pull the entire plant out.
Cut down the middle of the crown between the buds to divide the clump into parts. Each division should have at least one or two buds and a substantial portion of the root system.
Don’t let them get too dry. Place the separated part upright in the planting hole, 1.5 to 2 inches below the surface, with the buds 1.5 to 2 inches above the surface.
Water thoroughly and firm the soil surrounding the plant, but not too close to the bud. It is ideal for plants to be at least 3 feet apart. Position new plantings in areas with plenty of sunlight and sufficient drainage.
Avoid planting rhubarb in areas with a lot of trees and plants. When you plant rhubarb near trees and shrubs, the plants will struggle to compete for sunlight, water, and nutrients.
You should also mulch rhubarb by placing straw or other coarse material about 8 to 12 inches around the plant, especially if you transplant in the fall. Mulching gives the plants more time to establish themselves at their new location before the soil becomes too cold or freezes.
For excellent growth and high yields, rhubarb requires annual fertilizer treatments. Early in the spring, before growth begins, apply fertilizer. Use about 12 cups of all-purpose garden fertilizer, such as 10-10-10. Spread the fertilizer around each plant and lightly work it into the soil.
Add a 2- to 3-inch layer of rotting sterile compost as the primary source of fertilizer around the plants when development begins in the spring.
Manure also adds vital organic matter to the soil in addition to the nutrients it contains. You can add fourteen pounds of superphosphate (0-20-0) fertilizer per plant to the manure. Always remember to use sterile manure or compost to avoid spreading disease among your plants.
Let’s look at some pro suggestions on how to harvest your rhubarb, diseases, and insects now that you know the fundamentals of how to grow rhubarb.
Pro-tip #1 – Harvesting
For the first two years following planting, you should not harvest rhubarb as this approach promotes the growth of the crown and roots. Harvest for only four weeks during the third season. In the fourth year, begin complete harvesting.
Stalks should be cut back for 8 to 10 weeks, finishing in mid-June. The rhubarb plants will weaken and produce less the following year if you harvest your crop over a more extended period.
At any point in time, do not remove more than 2/3 of a plant’s completely formed stalks. Instead, wait until the stalks reach a length of 10 to 15 inches. Then take hold of the stem beneath the leaf and pull it up and to one side to remove it from the plant.
You can eliminate the leaves by cutting them just below the soil surface and discarding them. You can store the fresh rhubarb stalks in the refrigerator for 2 to 4 weeks in a plastic bag.
Pro-tip #2 – Diseases
Phytophthora crown, sometimes known as “root rot,” is a devastating rhubarb disease. Small, recessed lesions at the base of the stalks quickly grow, resulting in wilted leaves and stalk collapse.
The crown and roots start to deteriorate and turn brown or black.
Set disease-free plants in a location where rhubarb hasn’t been grown for 4 to 5 years to prevent root rot. Planting in well-drained soil can also help prevent root rot.
If your soil isn’t draining well, mound it up and create a raised planting bed, as this helps with drainage. Rhubarb is susceptible to diseases other than root rot. You can avoid most issues by planting it in well-drained soil in a sunny, well-ventilated area.
Pro tip #3 – Insects
Rhubarb curculio is a big, rusty snout beetle that measures approximately 3/4 inches in length. It punctures the stalk, causing slight injury but no severe harm. Rhubarb curculio lays eggs in the stems of wild docks.
Weed removal near rhubarb plantings in July will help suppress this pest. The rhubarb stem borer is an insect that spends the winter as an egg on grassy weeds. You can control this pest by removing grassy weeds from around the planting area.
How to grow rhubarb is straightforward for any beginner, which is why it is such as pleasure to grow this plant. Rhubarb requires little maintenance, can be grown in almost any climate, and is beneficial in many aspects.
You can harvest rhubarb from early spring until mid-summer. After that, you should stop harvesting to allow the plant to recover. They will conserve energy to survive the winter.
Remember that only the rhubarb stalks are edible. You should always discard the leaves since they contain oxalic acid, which is potentially toxic.
Tyler C Rich is the founder and chief editor at TopsyGardening.com. An experienced gardener and a professionally trained agriculture development expert, Rich has worked in the gardening and landscaping industry for more than a few decades. Although he has retired, his spark for developing the best urban and indoor gardens has not faded a bit. He uses TopsyGardening.com as a platform to come across enthusiastic gardeners and share the unique insights he has acquired through years of experience. Rich is interested in aquaponics and technology apart from conventional gardening techniques.