The ultimate rhubarb guide to growing, harvesting, preserving and cooking with rhubarb. Get lots of tips for growing this easy perennial food plant plus delicious recipe ideas for both sweet and savory dishes.
This rhubarb guide is a part of a continuing series of produce Ultimate Guides where you can find all kinds of growing information and tips as well as delicious recipes, both fresh and preserved, for a specific fruit or vegetable. See more fruit and vegetable guides here.
Rhubarb is one of those edible plants that’s considered a vegetable, but used like a fruit – in fact a US court decided in the 1940s that it was a fruit for import regulations because that’s how it’s often used (source).
It’s probably considered a bit unusual or old-fashioned, but it has some great qualities and lends itself to some fantastic recipes, so I really recommend growing it.
One reason is that rhubarb is a perennial plant and once established in a place that it likes it’s pretty carefree, coming back every year with minimal care.
So you need a permanent place – a rhubarb patch – where it can happily live and provide you with some of the first fruits of the gardening season year after year.
Another reason is that rhubarb is such a versatile plant to cook with and preserve – it can become a chutney for savory foods, ice cream sauce, pie and cake filling, jam, cookie bars, drinks and more.
Even so, it is still a mystery to some because it’s not a normal thing we find regularly in our supermarkets.
I often get questions asking what to make with rhubarb or how to grow it, so I’m putting all the rhubarb growing information and recipes that I’ve collected into one ultimate rhubarb guide so you’ll have one place to come for rhubarb answers.
Did you know that rhubarb is a member of the buckwheat family? So weird, right? It also has good amounts of vitamins C, K, and the mineral magnesium as well as some fiber and protein.
We eat the stalks of a rhubarb plant and they are known to be quite tart, which is why many recipes call for quite a bit of sugar. I’ve found I can easily use less to get a nice sweet-tart flavor, so my recipes use less sweetener and many use a natural sweetener, too.
The large leaves of the plant are poisonous (I always feel sorry for the people who discovered stuff like this, don’t you?), so they should be composted after harvesting the stalks.
Rhubarb leaves contain oxalic acid – in addition to other compounds that may be bad for humans (see this article for more on this). Other vegetables have oxalic acid, too, like spinach, chard, broccoli, cauliflower and brussels sprouts – only in smaller amounts which you can lower even further by blanching and draining the water.
However, you would need to eat a large amount of rhubarb leaves to be considered to be toxic, though small amounts may cause digestive distress.
According to the article linked above, in WWI Britain encouraged eating rhubarb leaves to help with food shortages and there were numerous illnesses and one death, which has not been reported with eating spinach and chard.
Based on this and other sources like this I will continue to advocate growing this lovely edible plant for it’s stems only and composting the leaves.
Rhubarb is a hardy perennial vegetable that produces tasty tart stalks in early spring. While cold temperatures are necessary to trigger new growth, providing some care as the plant goes dormant will ensure the crowns and roots remain healthy for many years of abundant harvests. Follow this guide to properly winterize your rhubarb for a bountiful spring crop.
Stop Harvesting in Early Fall
It’s important to stop harvesting rhubarb stalks several weeks before the first fall frost in your area, usually by early October. This gives the plant time to recover its energy stores in the roots and crowns before going dormant. Allow any remaining flower stalks to die back naturally and let the leaves yellow and wither on their own. This signals to the plant that it’s time to prepare for winter dormancy.
Remove Dead Leaves and Stems
Once the leaves have completely died back after the first hard frost trim off all the brown foliage. This removes hiding spots for overwintering pests and exposes the crown buds to the cold which helps trigger dormancy. Take care not to damage the crowns as you cut away the dead leaves.
Apply Nutrient-Rich Compost or Fertilizer
Before the ground freezes, work 2-3 inches of aged compost or a balanced organic fertilizer into the soil around your rhubarb plants. This feeds the beneficial soil microbes over winter while also protecting and nourishing the crowns for next year’s growth.
Mulch Crowns After Ground Freezes
After several hard frosts when the ground has frozen solid, apply a 4-6 inch layer of straw, leaves, or other loose organic mulch over the rhubarb crowns This insulates against dramatic temperature fluctuations without blocking the cold exposure needed for proper dormancy. Wait for a hard freeze so rodents aren’t tempted to nestle into the mulch.
Consider Protective Structures in Extreme Cold
In zones with very cold winters, a cloche, cold frame, or hoop tunnel over the plants provides extra insulation while still allowing airflow. Be sure to remove any plastic or fabric coverings once temperatures warm above freezing in late winter so growth isn’t triggered too soon.
Divide Overgrown Plants in Early Spring
If plants are overcrowded with woody cores, early spring before growth resumes is the time to divide them. Carefully cut the roots with a sharp knife, ensuring each new division has 2-3 healthy buds. Replant divisions 2-3 feet apart.
Allow Time to Recharge after Division
Avoid harvesting any rhubarb stalks the first spring after division or starting new plants. This gives divided plants time to build up energy reserves. Just remove flower stalks as they appear. One full season of uninterrupted growth is ideal before harvesting again.
Start Seeds in Winter for New Plants
For an extended harvest, start rhubarb seeds indoors in late winter and transplant outside after the last spring frost. Prepare seeds in January and grow under lights until ready to harden off in April.
Proper winter care ensures rhubarb crowns survive cold and wake vigorously in spring. Follow these tips for winterizing your rhubarb and you’ll be rewarded with years of abundant early harvests.
Red or Green Stalks?
I didn’t know until we moved into a new house with an established rhubarb patch that not all rhubarb varieties have red stalks. Some produce mostly green stalks with barely a hint of red.
The green stalked rhubarb is closer to the wild rhubarb, with newer varieties having been bred to be redder, like ‘crimson red’ and ‘valentine.’
I’ve cooked with both types and while there is no flavor difference, the food all looks better using red stalks. They make the jam pretty (it’s a dull brown color with green stalks) and produce wonderful red pockets in muffins and breads.
Green stalk rhubarb also tends to produce more flower stalks (some of the red varieties will not produce flowers at all), and when the flowers form, the stalks can be a bit dry and stringy.
However, the green stalk variety is hardier and easier to grow than the more popular red colored plants, so if you’re having problems getting rhubarb established, switching your variety may be an option for you.
Ultimate Rhubarb Guide – How to Grow Rhubarb
Rhubarb is most typically planted as one-year-old crowns, either bare root in very early spring or from potted plants in later spring.
Plant in the spring as early as you can in full sun and amend the soil a bit with compost before planting rhubarb crowns about an inch below the surface.
TIP: in warmer climates, rhubarb may do better in partial shade, though the stems will not grow as thick.
If planting more than one plant, set them at least 3 feet apart – a well established plant can grow huge!
Do not harvest the stalks at all the first year after planting to allow the plant time to grow with its full energy (although if it looks really healthy, it probably wouldn’t hurt to harvest 2 or 3 stalks to make some muffins with!).
Water well and consistently throughout the growing season, especially in the plant’s first two years.
After that, I’ve found them to be fairly drought resistant – they will die back if not watered, but will produce again the next spring. Of course that’s not the way to get the best, biggest stalks, but if you can’t provide water throughout the entire season once it’s established, it should be okay.
The only fertilizer it needs is a yearly topping of compost. Keeping the ground mulched with a layer of the compost, grass clippings or straw is a way to keep the ground moist as well. Just keep any mulch away from the crown of the plant, which can encourage rot.
To prepare your plant for winter, after the first hard frost, cut back any remaining stalks and dress with a light 2 inch layer of compost, leaves, or hay to protect the roots through the winter.
The only other thing to remember is to remove any flowering stalks that may appear (as mentioned, some varieties form more of these than others), as they take away the plant’s energy as well as cause the stalks to degrade in quality.
Established clumps can be divided every 4 to 5 years – when the stalks get small and spindly or when the crown is visibly crowded. This will help the plant keep growing nice thick stems.
You can dig around the edges and trim the crown down to 4 or 5 buds or you can dig most of the plant up and gift somebody with a rhubarb plant.
How To Prepare Rhubarb For Winter – Allotment Gardening For Beginners
FAQ
Do you cut back rhubarb for winter?
Yes, it is generally recommended to cut back rhubarb in the late fall or early winter after the foliage has died back naturally from frost.
How do you take care of rhubarb at the end of season?
Let it grow wild all summer. In the fall (depending on your geographical location), the rhubarb stalks will wither and die. Remove the dead stalks and leaves from the top of the rhubarb plant and place them around the plant in a circle. This let’s the nutrients fall back into the soil.
Do you need to cut leaves off rhubarb before freezing?
How To Cut and Freeze Rhubarb
Here’s all you need to do: Wash the rhubarb stalks and trim the ends. Remove the leaves, as they are poisonous. Cut the rhubarb into 1-inch pieces, just like you would cut celery.
How do you store rhubarb for the winter?
Cut the rhubarb into manageable lengths. Lay the pieces on a tray in a single layer and place in the freezer for 2 hours. Once frozen, you can decant the rhubarb into airtight containers or freezer bags. Frozen rhubarb can be safely kept in the freezer for up to 12 months.