How to Grow Rhubarb: A Complete UK Planting, Feeding and Harvesting Guide

Rhubarb is about as close as British gardening gets to something for nothing. Plant a crown properly, feed it once a year, and it will crop every spring for the best part of a decade with almost no attention in between. It is hardy, it is unbothered by our climate, and it produces at exactly the time of year when there is nothing else to pick.

This guide covers everything from choosing a variety and planting a crown to feeding, forcing, harvesting properly and dealing with the handful of things that go wrong. If you already have an established plant that needs splitting or re-siting, see our companion guide on how to transplant rhubarb.

Choosing a variety

Variety matters more than most people expect, mainly because it determines when you pick. Two plants - one early, one maincrop - will stretch your season from March to early July. If you only have room for one, an early variety earns its keep because it arrives when nothing else does.

Crowns, potted plants or seed?

• Bare-root crowns (recommended). Sold dormant from autumn to early spring, usually as a chunk of root with one to three visible buds. Cheapest, easiest to establish, and true to variety. Plant as soon as they arrive.
• Potted plants. Available in growth through spring and summer. More expensive but you can plant them almost any time as long as you water well. Useful if you have missed the bare-root window.
• A division from a friend's plant. Free, and the fastest route to a productive crown - provided the parent plant is healthy. See how to lift and divide a crown for the correct method.
• Seed. Possible, but slow and variable - seedlings do not come true to type, and you are looking at three years before a worthwhile harvest. Only worth it if you enjoy the process.

Where to plant rhubarb

Rhubarb stays put for five years or more, so it does not belong in a crop rotation. Put it at the end of a plot, along a boundary, or in a bed of its own.

• Sun: open and sunny is best. It survives light dappled shade but produces thinner, slower stalks.
• Soil: deep, rich and moisture-retentive but never waterlogged. Rhubarb is a heavy feeder with a big root system.
• pH: around 6.0–6.8. Most UK garden soil is fine untouched.
• Drainage: the one non-negotiable. Winter waterlogging causes crown rot. On heavy clay, plant on a low mound or in a raised bed.
• Space: 90cm (3ft) between plants and from any wall, hedge or path. A mature crown is a metre across and shades out anything beside it.
• Avoid: under trees (dry, shaded root competition) and frost pockets that sit wet.

How to plant a rhubarb crown

Best time: November to March, while the crown is dormant. November is ideal - the soil is still warm enough for roots to settle before winter.

Growing rhubarb in containers

It can be done, but rhubarb is a big, hungry, thirsty plant and a small pot will simply starve it.

• Use a container at least 50cm (20in) wide and deep - half-barrel scale.
• Fill with soil-based compost such as John Innes No.3, enriched with well-rotted manure. Multipurpose compost alone is exhausted by midsummer.
• Check drainage holes are clear and raise the pot on feet.
• Water far more often than in open ground, and feed with a general-purpose fertiliser through spring.
• Refresh the compost and divide every two to three years rather than five.

Containers dry out fastest exactly when restrictions bite, so stored rainwater is worth having - see our guides to water butts and rainwater storage and watering kit for a hosepipe ban.

Watering, feeding and mulching

• Water in dry spells, particularly in the first two years and especially for container plants. Established crowns are fairly drought-tolerant but produce thin stalks if they go short in late spring.
• Mulch every autumn or late winter with a generous layer of well-rotted manure or compost, kept clear of the crown. This one job does most of the feeding.
• Feed in spring from the second year with a balanced general fertiliser, or a high-nitrogen feed if growth is sluggish.
• Remove flower spikes immediately. A tall, knobbly, cauliflower-like stem will appear on stressed or older plants. Cut it out at the base - flowering diverts serious energy into seed production.
• Let the leaves die back naturally in autumn. Once they have collapsed, clear them away so slugs have nowhere to overwinter.
• Keep weeds down by hand rather than by hoeing close in - the crown sits near the surface and damages easily.

Rhubarb year: month-by-month

When and how to harvest rhubarb

Restraint in the first two years is what produces a plant that crops heavily for a decade.

The right technique

• Pull, do not cut. Grip the stalk low down, twist and pull outward so it comes away cleanly at the base. Cut stubs rot back into the crown.
• Leave at least half the stalks on the plant at any time so it keeps feeding itself.
• Stop by early July. The plant needs the rest of the summer to rebuild reserves for next spring. Later stalks also get tough and more acidic.
• Cut the leaves off immediately and compost them. Rhubarb leaves contain high levels of oxalic acid and should never be eaten - but they are perfectly safe on a compost heap.

Forcing rhubarb for early stalks

Forcing means excluding light in late winter so the crown produces long, pale, tender, notably sweeter stems weeks ahead of the outdoor crop. It is the best thing you can do with rhubarb, and the easiest.

1. Choose an established crown - at least three years old and vigorous. Never force a newly planted or recently divided plant.
2. In January or February, clear away debris and cover the crown with a traditional terracotta forcer, a large upturned bucket, or a dustbin weighted down. Block any light gaps.
3. Wait roughly six to eight weeks, checking occasionally. Piling straw or manure around the outside speeds things up slightly.
4. Harvest the pale stems when they reach about 20–30cm, then remove the cover.
5. Give that crown the rest of the year off. Do not take any more stalks from it that season, and do not force the same plant two years running - forcing is genuinely exhausting for the crown. This is why it pays to have two or three plants and rotate.

Dividing and renewing the crown

After five or six years a crown becomes congested: lots of thin stalks instead of a few fat ones, and a woody, hollow centre with growth only around the edges. That is not a failure - it is the plant telling you it is due for division.

Lift the whole crown with a digging fork in the dormant season, cut it into sections each carrying at least one strong bud and a good chunk of root, discard the dead middle, and replant. One old crown will usually give you three or four vigorous new plants.

Problems and how to fix them

Kit worth having

Related guides

• How to transplant rhubarb: when and how to move a crown
• How to grow blueberries in the UK
• What to plant in September
• What to do in the garden in September
• Water butts and rainwater storage