Forcing Rhubarb for Early Spring Stems in December
December is the perfect month to start forcing rhubarb for those sought-after, sweet, pink stalks that appear weeks before the outdoor crop. With minimal effort, you can turn a mature rhubarb crown into a delicious early treat—ready for harvesting as soon as late January or February, long before the rest of the garden wakes up. Here’s your guide to forcing rhubarb for extra-early spring stems.
What Does It Mean to “Force” Rhubarb?
Forcing rhubarb means covering an established crown in winter to exclude light. This warmth and darkness signals the plant to sprout tender, pink stems earlier than normal, at the expense of the root’s stored energy. Forced rhubarb is milder, sweeter, and less fibrous—a special winter luxury.
When to Start Forcing in December
- Begin after the first frost has blackened the outdoor rhubarb leaves, and crowns are fully dormant (usually late November to early January).
- Only force healthy, mature plants at least three years old—over-forcing can weaken young crowns.
How to Force Rhubarb in December
- Prepare the Crown
- Cut away all old leaves and remove any weeds or debris from around the plant.
- Mulch lightly with compost or straw, leaving the top of the crown exposed.
- Cover the Crown
- Place a large, dark container over the rhubarb crown. Traditional “rhubarb forcers” are tall terracotta pots with a lid, but any large garden pot, bin, bucket, or even an upturned dustbin will work if it blocks out all light.
- For extra warmth and earlier stalks, heap straw, leaves, or compost around the outside of the pot.
- Leave in Place
- Do not water or feed; the crown uses stored energy.
- Shoots will appear after 4–8 weeks, depending on weather and your region.
Harvesting Forced Rhubarb
- Stems are ready for harvest when they are long, pink, and about 20–30 cm (8–12 inches).
- Remove a few sticks at a time by gently pulling or cutting, leaving the center stalks to grow.
- Try not to harvest more than half the total stems to avoid weakening the crown.
- Forced rhubarb is best eaten straight away—poached, stewed, or in crumbles.
Aftercare
- Uncover the crown once you’ve finished harvesting forced stems.
- Let the plant rest and recover—don’t force the same crown every year (alternate crowns if you have a big patch).
- Feed well in spring with compost or fertilizer to help roots replenish energy for next year.
Forcing rhubarb in December brings a taste of early spring bang in the middle of winter. The effort is minimal, but the reward—tender, pink stems for winter desserts—is truly luxurious.