Rhubarb is easy to grow and is a great choice for beginners and advanced growers alike. Especially if you want a low-maintenance option for your vegetable garden.
This hardy perennial is a must-have for longtime gardeners. But to be successful, you first need to understand how to properly care for it.
This guide will teach you everything you need to know to grow your own rhubarb, no matter your skill level. Find all the important information about soil, water, fertilizers, sun, temperature, pest control and more.
Quick care overview for rhubarb plants
Information about rhubarb
Rhubarb (Rheum rhabarbarum) is a perennial vegetable native to Asia and has been cultivated around the world for hundreds of years.
It has a long stem, or rib, with large green leaves at the top. Mature plants can be more than 4 feet wide and have red, pink, or green stems.
The leaves contain oxalic acid, which makes them poisonous and inedible (source). However, gardeners love the sour and sour taste of its stems. Popular for baking, preserves, desserts, sauces, etc.
These low-maintenance plants can continue to produce for 8 to 15 years with few pest or disease problems.
different types
There are many varieties of rhubarb, each with differences in cold resistance, stem color, size, and growth rate. But thankfully, they can all be cared for in the same way. Here are some of the most popular types:
Canada Red – This plant has short stems, red inside and out, and is softer than other varieties. Riverside Giant – This slow-growing, cold-hardy variety produces long green stems. MacDonald – This variety is popular because its long, soft pink stems are juicy and low in acidity. Victoria – One of the most popular varieties due to its subtly sweet taste and soft stems that are red on the outside and green on the inside.
durability
Rhubarb is a very hardy perennial that returns year after year in zones 3 to 8. Temperatures as low as -20°F (-28°C) will not cause damage.
In fact, it needs cold weather to produce new stems each year. It may be difficult to grow rhubarb in your area without freezing temperatures.
How does rhubarb grow?
Edible fibrous stems grow from buds that form around the crown or root ball of the tree. Each year, a cluster of new buds grows outside of the previous year’s buds, gradually increasing the width of the plant.
Large, wide green leaves grow from the top of each stem. On mature plants, clusters of small flowers may develop into tall panicles in spring.
As the summer gets warmer, the stems become thinner and shorter as plants focus on conserving energy for next year’s bumper harvest.
Related article: How to make rhubarb jam: Easy recipe
Where to grow rhubarb
In cool zones of 3 to 5 degrees, choose a location in full sun to encourage the fastest growth. In warm zones 6 to 8, find a spot with partial afternoon shade to protect from the hot sun.
For best results, beds need rich, fertile, well-drained soil. A location that is not too humid and remains constantly moist is best.
When to plant
Plant Rhubarb balm as soon as the ground is workable in early spring. You can start them from seeds, but they take several years to fully mature.
Dig a deep hole and fill it with compost or well-rotted manure. Add a slow-release fertilizer and plant the crown 1 to 2 inches deep in the soil.
A single rhubarb plant will grow larger over time, so plant them 3 to 4 feet apart to give them plenty of space and avoid crowding them.
Rhubarb plant care and growth instructions
Now that you have the right location in mind, it’s time to talk about how to care for rhubarb. The tips below will help you easily add them to your garden.
sunlight
Rhubarb needs 6 to 8 hours of sunlight to produce healthy stems and store enough energy in the crown to grow each year.
Unless you live in a warm climate (zones 6-8), choose a location that gets full sun. If this is the case, avoid sunburn by providing shade during the hottest parts of the day.
water
Although rhubarb can tolerate short periods of drought, it grows best with constant moisture and does not like too long a drought. When about 1 cm of the soil is dry, give it plenty of water.
Never soak to the point where water collects or the ground becomes damp, as over-soaking can cause crown rot.
Add mulch around the base of your plants to help retain moisture, especially in the summer when temperatures rise. Compost, hay or shredded bark are perfect for this. Stop watering in the fall when the plant goes dormant and the leaves die back.
Related article: How to make rhubarb at home
temperature
These hardy plants don’t like heat and grow best in spring and early summer when temperatures are between 40 and 75°F (4.4 and 23.9°C). Anything above that temperature can cause drought stress, wilting, bolting, or scorching.
When temperatures drop, plants enter dormancy from fall to winter. But that’s good. This is because they need to rest below 40°F (4.4°C) to produce new stems the following spring.
fertilizer
Rhubarb is a highly nutritious plant and will benefit from regular application of a balanced all-purpose vegetable fertilizer throughout the spring and summer.
Use an all-purpose solution twice a month during spring and early summer, or top-dress with slow-release granules before spring dormancy ends.
Add compost or well-rotted manure in early spring, and mix slow-release granules into the soil every month. Alternatively, apply a liquid such as compost tea or fish emulsion every two weeks.
soil
One of the reasons rhubarb is so easy to care for is that it can grow in almost any type of soil as long as it drains well. However, the ideal mixture is rich, fertile, porous, and loamy.
It should also be slightly acidic, or between 6 and 6.8 on a ph probe. If your soil is alkaline, you can use slow-release acidifiers to improve your soil.
Poor-quality garden soil can be improved before planting by digging a deep hole and adding compost, well-rotted manure, or slow-release granular fertilizer. Alternatively, you can top dress the plants.
pruning
You don’t have to worry about pruning your rhubarb. Rhubarb grows well without pruning. However, regular trimming will help maintain the plant’s appearance and control its size.
Remove dead or damaged stems by simply twisting or cutting them. Use sharp pruning shears to cut off flower stalks as they appear. This allows the plant to return energy to the canopy to store it for next year.
propagation
If your rhubarb is older than five years, you can remove new clusters or divide the crown in late winter or early spring, when the plant is still dormant.
Divide them using a sharp, sterile garden knife, making sure each section contains at least one bud. Share it with a friend or replant it with enough space.
pest control tips
Although the plant is usually pest-free, the rhubarb curculio beetle prefers to feed on and lay eggs on the stems.
These pesky insects overwinter in plant debris and dead leaves, so be sure to clean your garden in the fall to prevent insect damage.
Holes in the stems or oozing sap are signs of infection. Remove bugs from plants by hand and dropping them into a bucket of soapy water.
Disease management tips
Crown rot is a common problem in heavy, poorly drained soils and is usually caused by overwatering. The main symptoms include wilting, yellowing of leaves, and softening of stems.
Spot disease is a fungus that can be spread by water and wind. Red, yellow, or brown circular lesions appear on the leaves. Keep old plant debris and root water away from the ground to prevent it from splashing onto the leaves.
If you notice spots on the leaves, remove and destroy the infected leaves immediately to prevent the disease from spreading.
Tips for harvesting rhubarb
In the second year of rhubarb growth, you can start harvesting lightly by removing just a few of the large outer stalks.
By the third year, as soon as the stems reach 12 to 18 inches in height, you can remove up to 1/3 of the plants with each harvest.
The best way to pick is to hold the stem firmly in your hands and twist it from the base. Remove and discard leaves immediately. It is not edible and the stems will become soft if left for too long.
Related article: How to freeze rhubarb (with or without blanching)
Troubleshooting common issues
Rhubarb is low-maintenance and rarely has problems, but no plant is problem-free. If you run into any of these common issues, use my tips to resolve the issue.
thin and thin stem
The stems may become thin due to lack of light, nutritional deficiencies, aging, etc. If your rhubarb is in full sun, try fertilizing it by adding an all-purpose liquid or slow-release granules.
If the sun and nutrients are OK and the plant is between 5 and 10 years old, it may be time to divide. You can rejuvenate the crown by cutting it into several parts or removing clusters of new buds and transplanting them.
brown spots on leaves
Spot disease, a fungal disease, often causes brown spots to develop on rhubarb leaves. This can be caused by moisture on the leaves, poor airflow, or old plant debris.
The best option is to remove and destroy the affected leaves. Keep the base of the plant clean, avoid overhead watering, and make sure the plant is not crowded.
FAQ
Rhubarb is fast-growing but cannot be harvested until the second or third year, depending on the variety.
Rhubarb does not spread by sending out branches or runners, but each year the plant widens as new buds develop outside the crown.
Yes, rhubarb is easy to grow as it tolerates a wide range of soils, is resistant to pests and diseases, is cold hardy, and requires little care.
Rhubarb is a vegetable. People often mistake it for fruit because it is frequently used in sweet recipes such as jams, jellies, and desserts to offset the acidity.
Rhubarb is a hardy perennial that returns year after year in zones 3 to 8. It does not grow well in warmer climates, as it needs cold winters to produce lots of thick, edible stems.
Yes, rhubarb plants will return annually to growing zones 3-8.
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