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Planting and Growing Rhubarb

Botanical Name
Rheum rhabarbarum
Grown as
Perennial
USDA Zones
3a
3b
4a
4b
5a
5b
6a
6b
7a
7b
Toxicity
Toxic to Dogs and Cats
Sun Exposure
Full Sun
Partial Sun
Water Needs
Moderate
Height
3-6 feet
Spread
3-6 feet
Soil pH
Acidic
Neutral
Special Features
Cut Flower
Low Maintenance
Attracts Pollinators
Deer-resistant
Rabbit-resistant
Resilience
Cold Hardy
Plant Type
Vegetables
Written By: Catherine Boeckmann Executive Digital Editor and Master Gardener

What grows for 10 years or more, suffers from almost no pests, and is refreshingly easy to care for? It’s rhubarb! This perennial vegetable has tart-flavored ruby or green stems used to make pies, crumbles, cakes, jams, and sauces. Learn how to plant, grow, and pick rhubarb correctly.

Rhubarb is easy to grow but needs a dormancy period to thrive and produce an abundance of huge stalks. Rhubarb does best where the average temperature falls below 40ºF (4°C) in the winter and below 75ºF (24°C) in the summer.

What’s lovely about rhubarb is that it’s a perennial: A healthy plant will remain productive for 10 years or more. For that reason, rhubarb should be planted in its own space in any corner of the garden where it can grow undisturbed. Rhubarb grows well in soil amended with plenty of well-rotted manure or compost; this has inspired some gardeners to plant it near their compost piles!

Planting

When to Plant Rhubarb

  • Rhubarb can be planted in late fall or early spring.
    • Plant rhubarb crowns after dormancy has set in in the fall, and you’ll have rhubarb cropping in the spring!
    • In spring, plant crowns when the soil is workable, when the roots are still dormant, and before growth begins (or as plants are just beginning to leaf out). If you have a temperature gauge, soil temperature should be 50°F minimum.

Spacing for Rhubarb

Where to Plant Rhubarb

Rhubarb grows best in full sun but will tolerate partial shade.

Choose a site with soil that is well-draining and fertile. Good drainage is essential, as rhubarb will rot if kept too wet. Mix compost, rotted manure, or anything high in organic matter into the soil. Rhubarb plants are heavy feeders and need this organic matter. Learn more about soil amendments and preparing soil for planting.

Rhubarb gets big! It can grow to 2 to 3 feet tall and wide. Make sure you choose a site where it won’t be crowded. 

How to Plant Rhubarb

  • Plant 1-year-old rhubarb crowns, which you can find at a garden center or nursery, or order online. Plants will be sold as bare-rooted specimens or young plants already growing in pots, ready for transplanting. (Rhubarb can be grown from seed, but this is not recommended.)
  • Before planting, eliminate all perennial weeds in the planting site.
  • Dig large, bushel-basket-size holes.
  • Space rhubarb plants about 2 to 4 feet apart and 3 to 4 feet between rows.
  • Plant crowns so the eyes are about 2 inches below the soil surface with buds facing up.
  • Water well at the time of planting.

Check out this video to learn more about how to plant rhubarb:

Growing

Overcrowding is a common problem with rhubarb and can lead to subpar growth. Dig and split rhubarb roots every 3 to 4 years. Divide when plants are dormant in early spring (or late fall). Divisions should have at least one large bud on them. 

  • Mulch generously with a heavy layer of straw to retain moisture and discourage weeds.
  • Water your plant well and consistently. Rhubarb needs sufficient moisture, especially during the hot, dry summer days.
  • Remove seed stalks as soon as they appear, as they will only drain energy from the plant that could be used to produce stalks or roots.
  • Each spring, apply a light sprinkling of fertilizer (10-10-10) when the ground is thawing or has just thawed. See your local frost dates.
  • In the fall, remove all plant debris. Once your ground freezes, it’s best to cover rhubarb with 2 to 4 inches of organic mulch, preferably well-rotted compost. By adding nitrogen to the soil, you’re preparing the rhubarb plants for a good spring season.

Rhubarb leaf

Harvesting

Do NOT harvest any stalks during the first growing season. Harvest sparingly in the second year. This allows your plants to become properly established.

  • After a plant’s third year, the harvest period (rhubarb season!) runs 8 to 10 weeks long, lasting through mid-summer.
  • Harvest stalks when they are 12 to 18 inches long and at least 3/4-inch in diameter. If the stalks become thin, stop harvesting; the plant’s food reserves are low.
  • Grab the base of the stalk and pull it away from the plant with a gentle twist. If this doesn’t work, you can cut the stalk at the base with a sharp knife. To prevent the spread of disease, be sure to sanitize the knife before cutting. Discard the leaves.
  • Always leave at least two stalks per plant to ensure continued production. You may have a bountiful harvest for well over 10 years without replacing your rhubarb plants.
  • It was once believed that the entire rhubarb plant became toxic as summer temperatures rose. This isn’t true, although summer-harvested stalks usually have a tougher texture than those picked in the spring. Nevertheless, after midsummer (July), it’s best to leave stalks on the plant to allow them to gather energy for next year’s growth.

How to Store Rhubarb

Cut the rhubarb stalks and refrigerate in a covered container. Or, tightly wrap stalks in plastic or aluminum foil and refrigerate. Rhubarb can be kept fresh in the refrigerator for a couple of weeks.

Cut rhubarb stalks into pieces, place them in a covered container or zip-type plastic bag, and put them in the freezer. Frozen rhubarb will last about a year.

Pests and Problems

Pests and diseases are rarely an issue with rhubarb, but it may be affected by the following problems.

Rhubarb Pests and Diseases
Pest/DiseaseTypeSymptomsControl/Prevention
Botrytis (gray mold)FungusVaries; yellow/ brown/gray spots with water-soaked margins on leaves/flowers; gray mold; buds remain closed; stem lesions; wilt/rot; scorched appearance (“fire”) in some plantsDestroy infected parts/severely infected plants (do not compost); remove plant debris regularly; disinfect tools; good air circulation/sunlight; avoid overhead watering; prevent plant stress/injury; weed; rotation
Fungal leaf spotFungusVaries; leaf spots on lower leaves enlarge and turn brown/black; fuzzy growth or pustules in lesions; disease progresses upward; leaves dieDestroy infected leaves/ severely infected plants (do not compost); remove plant debris regularly; disinfect tools; resistant varieties; good air circulation; avoid overhead watering
Phytophthora crown and root rotOomyceteLeaves discolor/ wilt; dieback; oozing cankers near base; reddish brown discoloration of inner bark/wood; roots rot; plants slow-growing/stunted/dieDestroy infected plants and surrounding soil (do
not compost); prune out branch cankers; remove plant debris regularly; plant resistant varieties; prevent plant stress/injury; provide good drainage/do not overwater
Rhubarb curculioInsectWeevil-like beetle that bores into stalks/crowns; notches on stalks/leaves; holes in stalks leak sap; plants wilt/decayHandpick adults (appear in mid-May); destroy nearby host plants (sunflowers, thistle, dock) in mid-summer (July)
Slugs/snailsMolluskIrregular holes in leaves; slimy secretion on plants/soil; young stems “disappear”Handpick; avoid thick bark mulch; use copper plant collars; avoid overhead watering; lay boards on soil in evening, in morning lift and dispose of pests in hot, soapy water; drown in deep container of 1/2 inch of beer or of sugar water and yeast sunk to ground level; apply 1-inch-wide strip of diatomaceous earth

Toxicity
The stalks are the only edible part of the rhubarb plant. These have a rich, tart flavor when cooked. The leaves of the rhubarb plant are toxic. They contain an irritant called oxalic acid, so be sure that they are not ingested.

Types

These common varieties have attractive red stalks and excellent growers: 

  • ‘Canada Red’
  • ‘Crimson Red’
  • ‘MacDonald’
  • ‘Valentine’

In addition to the previous four, there is a reliable, green-stalked cultivar named:

  • ‘Victoria’

Wit and Wisdom

Rhubarb originally came from Asia. It was brought to Europe in the 1600s and to America shortly thereafter. It thrives in areas with a cooler climate, making it popular in northern gardens.

Rhubarb has many other uses, from medicinal to cosmetic. See how to naturally lighten your hair with rhubarb. 

Vegetables

About The Author

Catherine Boeckmann

Catherine Boeckmann

Executive Digital Editor and Master Gardener

Catherine Boeckmann loves nature, stargazing, and gardening, so it’s not surprising that she and The Old Farmer’s Almanac found each other. She leads digital content for the Almanac website and is also a certified master gardener in the state of Indiana.

Read more from Catherine Boeckmann

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Comments

<span>Kris</span> Sat, 05/25/2019 - 15:37
Hi I live in southwest Wyoming at 6300 ft - high desert. I’m getting ready to plant some rhubarb but understand it needs full sun. I have a 9x24 plot on the east side of our house that gets morning sun until about 1 or 2 in the afternoon (a total of about 6 or 7 hrs of sun) then after that it’s shaded. How well do you think it would perform there?
<a title="View user profile." href="/author/editors">The Editors</a> Tue, 05/28/2019 - 16:36

Hard to tell, but try it. Most sources advise, as we do above, that rhubarb needs "full sun." That usually means around 8 hours of sun, including midday/afternoon sun. If there is any way you can give the plant a southern exposure—even as a single plant outside of your plot—you may be able to increase its sunshine. If critters are a concern, know that they seldom go after (eat) it, and it will remain pretty self-contained for 4, 5, or even 6 years (before dividing is needed). Just prep the soil with rich organic matter. Hope it succeeds for you!

 <span>Sheila</span> Sun, 05/19/2019 - 11:55
I will be moving from NY to FL and would like to bring my rhubarb plants and understand they won't survive the winter because it doesn't get cold enough. Would the plants survive if I put them in a spare refrigerator in the winter or refrigerate or freeze the roots?
<a title="View user profile." href="/author/editors">The Editors</a> Tue, 05/21/2019 - 16:07

Rhubarb does not really do well in Florida. Gardeners trying to grow it in the deep south are advised to treat it like an annual. Buy new crowns, freeze them for 6 weeks, and then plant. You could try your way for the first year and see how your plants do. Be sure to give them a little bit of water while you are cooling them.

 <span>Melissa Sheldon</span> Thu, 05/09/2019 - 21:06
Hi, I’ve been told that you must cut off the flower stalk to keep the rhubarb growing and I’ve been told it doesn’t matter. Is it necessary to cut off the flower stalk?
<a title="View user profile." href="/author/editors">The Editors</a> Mon, 05/13/2019 - 15:58

It's better to cut the flower stalk in order to prevent the plant from wasting energy on developing flowers and seeds over more stems and foliage. 

 <span>Dee Dee</span> Thu, 05/09/2019 - 12:52
Hello, My rhubarb plant flower stalks became rather large before I got the chance to cut them. Since they were so big there were many leaf stalks coming off the main flower stalk. Are the stalks from the flower stalk edible? They look just like the regular rhubarb stalks, and I don't like to waste anything, so I was hoping they are also edible and use them like I would regular rhubarb stalks. Thank you.
<a title="View user profile." href="/author/editors">The Editors</a> Thu, 05/09/2019 - 17:33

Hi there. I couldn't confirm that it is absolutely safe, so I think it would be best not to harvest those leaf petioles that come off of the flowering stalk itself. Some sources say that the flowering stalk itself is not edible. The flower buds can be eaten when specially prepared, but not the stalk they are attached to, nor the papery covering surrounding the buds, or the leaves along the stem. All in all, it's best to just discard the entire flowering stalk to be on the safe side. Or, you can place them in a flower arrangement, away from children and pets.

 <span>Gail</span> Wed, 05/08/2019 - 07:29
I didn't read anything about a 2nd harvest. I always take second clippings the first part of September. First cut is typically May. I am in Zone 4. No problems with my bounty. Am I doing wrong by taking a 2nd harvest??
<span>Linda Coulthard</span> Sat, 07/20/2019 - 17:56
I have been eating the leaf stalks on the flower stalks of rhubarb all my life and have not suffered any ill effects. I'm 70 years old, so if there were a problem I think I would have noticed by now.