Rhubarb is a hardy perennial plant that grows tasty, sour stalks in early spring. Even though it needs to be cold to start new growth, taking care of the plant while it’s dormant will keep the crowns and roots healthy for many years of good harvests. Follow these steps to make sure your rhubarb is ready for winter so you can get a big crop in the spring.
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
Following the first hard frost, cut off all the brown leaves once the plant has lost all of its leaves. This gets rid of places where pests can hide over the winter and lets the cold hit the crown buds, which helps them go into dormancy. When you cut off the dead leaves, be careful not to hurt the crowns.
Apply Nutrient-Rich Compost or Fertilizer
Before it freezes, add two to three inches of aged compost or a balanced organic fertilizer to the soil around your rhubarb plants. This feeds the good microbes in the soil over the winter and protects and feeds the crowns for growth next year.
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 have too many woody cores, divide them in early spring before they start to grow again. Carefully cut the roots with a sharp knife, making sure that each new section has two or three 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.
Besides having more flower stalks, green stalk rhubarb sometimes doesn’t have any flowers at all, and when they do, the flower stalks can be a bit dry and stringy.
But the green stalk variety is hardery and easier to grow than the more common red plants. If you’re having trouble getting your rhubarb to grow, you might want to try a different variety.
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 you plant more than one, space them at least 3 feet apart. A plant that is well-established can get very big.
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, rhubarb should be trimmed back in late fall or early winter, after the leaves have 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?
Rhubarb can be cut and frozen. To do this, just wash the stalks and cut off 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.