Growing Rhubarb

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growing rhubarb in the garden

Rhubarb grows best in cooler climates.

Rhubarb likes cold climates. This big plant growing in coastal Maine sprawls to fill an entire corner of a vegetable garden.

One of spring’s garden harbingers, rhubarb stems burst through soil early in the growing season. The tart, colorful stems grace pies and jams with tangy flavor that is typically tamed with sugar or teamed with sweet strawberries.

A true perennial, rhubarb adds sculptural beauty to the garden with its blocky stems and large leaves. While leaves offer textural beauty, they’re not part of the harvest package. Rhubarb leaves contain high concentrations of oxalic acid and shouldn’t be eaten. When growing rhubarb, harvest the stems, then remove leaves and add them to the compost pile.

Rhubarb grows best in zones where the ground freezes in winter. Plants require an extended chilling period with temperatures below 40 degrees to produce a crop of stems. As a result, rhubarb is commonplace in gardens throughout the coldest sections of the country, although it can be grown as far south as Zone 7.

Soil, Planting, and Care

A true perennial, rhubarb plants can yield harvests 5 to 8 years or longer. Once plants are established, they don’t transplant easily, so choose your planting site carefully. Rhubarb thrives in full sun but will yield to light shade. Select a location that gives plants ample room; individual rhubarb plants can measure up to four feet wide and tall.

Plant crowns in spring as soon as soil is workable. Tuck plants into slightly acidic soil rich in organic matter; blend in plenty of well-rotted manure or compost. Rhubarb crowns require shallow planting (around 4 inches deep), but because plants are such heavy feeders, you should dig planting holes at least a foot deep. If your soil is heavy clay, plant rhubarb in raised beds.

Water newly planted crowns, and keep soil moist throughout the growing season. As summer heat arrives, mulch plants with a 2-inch-thick layer of organic mulch, such as compost, straw, or shredded bark. Replenish mulch throughout the growing season as needed to maintain 2-inch thickness. Fertilize at planting and every couple of weeks throughout the growing season with Bonnie Herb & Vegetable Plant Food.

Cut back rhubarb blooms when you see them. They take away energy from the plant.

When you see flowers like these, cut them off at the base of the stalk immediately. They sap energy that should go into growing nice stalks for next year.

In fall, when stems die back, remove all plant debris. Mulch plants after the ground freezes, covering crowns with 2 to 4 inches of compost or leaves.

Troubleshooting

Rhubarb plants have large leaves that get larger as the plant matures each year.

Rhubarb plants grow large leaves that need plenty of time through summer to gather strength for the next year’s harvest. As plants mature over a few years, the leaves will grow bigger.

Established plants need to be divided every 5 to 10 years. You’ll know it’s time to divide when stems are crowded and thin. Divide when plants are dormant, in early spring or fall. Dig and lift clumps, cutting roots into pieces about 2 inches across. Take care not to damage the buds on the top of each root section. Replant the best sections.

Few problems plague rhubarb. Crown rot settles in when soil drainage is poor. This disease damages terminal buds, which results in spindly, weak stems. The cure is to dig out and burn infected plants. Don’t replant rhubarb in areas where crown rot has damaged plants before.

Leaf spots can attack the plant, with the worst being red leaf, or Ramularia, which can ruin the stems. Cut away old foliage in fall to help prevent leaf spot, whose spores overwinter in the debris.

Rhubarb curculio occasionally attacks plants. Insects puncture leaf stalks from late spring to early summer as they feed and lay eggs. Damaged stems ooze sap and may begin to decay.

Harvest and Storage

After a few years in the garden, rhubarb plants will be stronger and will pop up each spring with pretty red stalks.

This is how a well-established clump of rhubarb leaves looks as the leaves emerge from the ground in spring.

Forget harvesting the year that you add rhubarb to the garden. In the second year after planting, harvest lightly, removing only a few stalks from each plant. From the third year on, harvest stems freely. To ensure continued production, take care not to remove more than one-third to one-half the stalks from any one plant during any one harvest.

To harvest, choose stems that are 12 to 18 inches long and reddish in color. Grasp the stalk near the base and pull it upwards, twisting the stem as you pull. You can also use a sharp knife to slice stems from the plant. Cut as close to the crown as possible without damaging it. After harvesting, remove the leafy portion and the base of the stem, leaving only the colored stalk.

Remove rhubarb leaves and use rhubarb stems for recipes.

After cutting the away the green foliage from rhubarb leaves, you will be left with pretty red stems for cooking.

Early spring stems offer the most flavor and tenderness; they’re ideal for pies. Stems harvested later in the season are often pithy. Reserve these stems for stewing, sauces, or jams.

Stop harvesting as stems get shorter and thinner. At this point, plants are storing up energy for next year’s harvest. Mature plants typically provide an 8- to 10-week harvest. In general, expect 2 to 3 pounds of stalks per mature plant per season.

For the best quality in cooking or freezing, use freshly harvested stalks. If that is not possible, keep cut stems up to 1 week in the refrigerator, although crispness diminishes with storage. You can refresh crispness by standing stored stems in water before using; however, the flavor will be slightly diluted. You can also chop stems and freeze the pieces in a plastic freezer bag for much later use.

FAQs

I planted rhubarb this spring. When can I start picking?

The rule of thumb is not to harvest rhubarb the year you plant it. Give plants time to produce a sturdy root system. The second year after planting, pick only a few stems from each plant. By not picking heavily, you’re allowing leaves to generate energy that enhances root growth. The third year is when you can start picking rhubarb by the armload.

White stalks are rising out of the center of my rhubarb plants. What are they?

Those stalks are the flowering stems. Remove them as soon as they appear. Allowing rhubarb to bloom takes energy that the plant might otherwise shift toward root growth, which will help fuel next season’s harvest.

How do I know when rhubarb is ready to pick?

Look for reddish stems 12 to 18 inches long. Smaller diameter stems offer best quality. Larger, fatter stems can be pithy and tough, especially later in summer and also if plants experience drought.

How do I harvest rhubarb?

Grab stems near the base and pull gently while applying a slight twisting motion. Take care not to injure the central bud, which will yield many more stems in the course of the growing season. Harvest up to one-third of stems from one plant at any one picking.

Can I harvest stems from a mature rhubarb clump all summer?

As long as clumps do not flower, you can continue to pick stems well into summer. Stop harvesting when stalks remain small and short. From this point on, the plants are storing energy for next year’s harvest season. Keep rhubarb well watered until frost.

My rhubarb was growing fine, then stalks began to fall over and rot. What is happening?

You’re dealing with crown rot, a fungus disease that sometimes attacks established clumps of rhubarb, especially those that need dividing. Once it attacks a plant, you’ll need to dig it up and destroy it. Do not re-plant rhubarb in the same spot where crown rot has affected a plant. The best way to avoid crown rot is to plant rhubarb in well-drained soil. Raised beds also help, as does dividing clumps when necessary.

My rhubarb patch is so healthy that plants are crowding one another. Can I divide them, and if so, when?

Many gardeners divide rhubarb every 4 to 5 years. You’ll know it’s definitely time to divide when stems are short, stringy, and dry. Use a sharp spade to slice a start from a rhubarb crown in early spring, before growth begins. Dig up as much root as possible. Divide the clump so that starts each have two buds. Plant buds 1 inch below the soil surface. If possible, try to leave the part of the original plant undisturbed, so you’ll be able to harvest from it this season.

30 thoughts on “Growing Rhubarb

  1. Hi, love your great tips & help…can I plant rhubarb in May or would Fall planting be better. Thanks for the expert advice!! P. S. I’m in CT.

    • Hi –

      Rhubarb is typically planted in the spring in the New England area of the United States. Although, I could not find a growing guide for rhubarb in Connecticut, this one from the University of New Hampshire extension is close to you. -danielle, Bonnie Plants

  2. wanted to know if it is true you have to wait a year or two after planting new rhubarb plants before consuming the stalks.

    • Hi Lil,
      Patience really is a virtue in this case. Like asparagus, it is best to wait a year before harvesting. Harvest lightly the second year. You can read more about this by clicking the harvest and storage tab here. -Danielle, Bonnie Plants

  3. I buy Bonnie rhubarb but I want the red kind instead of the green, how do I know if it’s red or green when I buy the starts

    • Hi Norman,
      You are growing a Victoria rhubarb. You will know all about the colors by knowing what variety you order or buy. This is a list of rhubarb varieties from Oregon State with their descriptions. -Danielle, Bonnie Plants

  4. Hello, this is my 2nd yr for the rhubarb plant it is in a shady area,late sun. it wants to stay close to the ground and the leaves on the bottom rot away, thanks Barbara

    • Hello,
      It may not grow very large without sufficient sunlight. In light shade, rhubarb will grow best with morning sunlight as opposed to late afternoon sunlight. Very shade conditions limit growth. Leaves that sit on the ground are prone to leaf spots and rots. You can just clip those leaves away. – Danielle, Bonnie Plants

  5. I just purchased your rhubarb plants from walmart. How do I know the age of the plants? Are they going to be “pickable” this season or do I have to wait until next year? Thanks! ~Amy

    • Hi Amy,
      Unfortunately, you will need to exercise some patience this season. These are new plants- you will be able to harvest next year. :) – danielle, Bonnie Plants

  6. I just bought a large rhubarb plant and put it in the ground.
    When I looked at it today I found ants crawling all over it. I have never had ants in my garden before. How can I get rid of them? I don’t want them to affect the rest of my garden.

    • Hello Mary,
      Ants can be beneficial pollinators in the garden; they will go after the honeydew secreted by other insects, and in the case of fire ants – they hurt! There are several options available to homeowners for veggie gardens. You can use ant baits labeled for vegetables in the garden as well as diatomaceous earth (which gets them as they walk across it). Insecticidal soaps are also used – directly sprayed on the ants. P. Allen Smith offers tips on companion planting for pest control here. – Danielle, Bonnie Plants

  7. I just purchased a Bonnie Rhubarb plant at a Home Depot in Overland Park, KS. Can you tell me which variety it is?? Thanks!!

    • Hi Brooke,
      You are growing Victoria rhubarb :) Danielle ,Bonnie Plants

  8. My rhubard is 6-9 inches tall and temperatures are predicted to drop to 25 degrees tonight. Do I need to cover my plants? Thank you

    • Hi Karen,
      Late frosts and freezes are common occurences in areas where rhubarb is grown. Once up and growing, you can protect the plant from those extremely low temperatures with a row cover or blanket. If freezes nip the plants, you’ll notice brown to black water soaked areas. New leaves are usually not too far behind. – Danielle, Bonnie Plants

  9. I bought a rhubarb plant from Lowe’s. It had two leaves. Another leaf/stem started to grow, and one died. This has literally been it’s life cycle – when a new leaf/stem starts to grow, one of the older ones die.

    I have not transplanted it into the ground yet. I was waiting until I had a good space and companion plants to go with it. Looks like they should have strawberry neighbors.

    Right now, it’s inside, under a grow light.

    Any suggestions on how I can change the new growth/death ratio?

    Any suggestions on the transplant? (I did read that you transplant once…and that should be all.)

    I want to put the plant into the ground this weekend.

    Thank you!

    • Hello Sary,
      Be sure and let your plants acclimate to the outside slowly. Take it out and let it enjoy the outdoors for several hours at time until it has adjusted to the outside sun and temperatures. I am thinking your rhubarb is not happy inside! Most vegetable plants are not. Yes, rhubarb is a perennial and will come back the following year from its roots so be sure and plant it in a good, organic rich area. It’s not hard – there are pointers on the Growing Rhubarb webpage! – Danielle, Bonnie Plants

  10. in an atlanta summer, would my rhubarb prefer dappled shade? or should i put it in pot and bring it inside for the hottest months?

  11. My rhubarb seems to start going to seed almost as soon as the stems start to grow can you tell me what I am doing wrong or do I have weird plants?

    • Hello Agnes,
      Rhubarb will flower and go to seed for a variety of reasons. Older plantings may flower more readily and may need to be rejuvenated by divison. Weather can play tricks on rhubarb too. Early, warm weather can ‘trick’ rhubarb into flowering as it is a cool season plant. Keep the flower stalks removed for better production. For more tips on rhubarb flowers, see this publication from Perdue Extension.
      -Danielle, Bonnie Plants

  12. Hello I live in Melbourne Australia and have rhubarb growing in pots. They take a LOT of water! Are there some varieties that have green edible stems, or should I wait till the stems are red? The plants are thriving and have been in for almost a year. Thanks!

    • There are some varieties with green stems. It’s best to know what you have before you harvest. If you had purchased a Bonnie plant in the U.S., I could tell you! And don’t eat the leaves, remember. Read our harvesting tab above. ~Mary Beth, Bonnie Plants

  13. i have just got 7 nice rhubarb plants(victoria kind) and i was woundering can i grow them in florida? if it helps to know i live in viera so it might help i am closer to the north i dont know.

    • Hi Jared,
      This link from your local Cooperative Extension site discusses the tricks to growing rhubarb in Florida. It does need chilling/freezing winter temps to perform at its best, so it should be treated like an annual in your garden. Happy growing, Mary Beth/Bonnie Plants

  14. What rhubarb plant will be best in Zone 3 mountains and where do I get them. Thanks Gail

    • Hi Gail,
      We can direct you to plant availability based on your zip code, as it varies by region and season. If you send your zip code to us via Customer Service (private message) or here (public post), we can check our growing schedules to see if we are supplying your area this fall. ~Mary Beth, Bonnie Plants

  15. Hi. I am wondering what variety of rhubarb would grow the best in zone 7. Can you help? Thanks. Barbara

    • Hi Barbara,
      The rhubarb that we sell will be a perennial in your Zone 7 garden. Consider yourself lucky, as those south of you would love to have this in their landscapes (myself included!) ~Mary Beth, Bonnie Plants

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