How to grow rhubarb — crowns, division, and harvest

How to grow rhubarb — crowns, division, and harvest

Safety warning — read this first. Rhubarb leaves contain high levels of oxalic acid and anthrone glycosides and are toxic to humans, dogs, cats, and horses. The ASPCA classifies the entire plant as toxic to pets, with the toxic principle being soluble calcium oxalates that can cause kidney failure, tremors, and salivation. Only the stalks are edible. Cut leaves off at the top of the stalk in the garden and compost them, or use them as a slug-deterrent mulch. Never feed leaves to pets, livestock, or children.

Rhubarb is the easiest, most forgiving perennial in a temperate kitchen garden — once you've understood the rules. Like a strawberry bed or a stand of raspberry canes, it earns a permanent corner of the plot rather than a slot in the annual rotation. A crown planted today will still be cropping in 2046 if you divide it occasionally and keep the leaves away from the dog. This guide covers planting, the make-or-break year-1 rule, forcing for super-early UK stems, and division.

Track your rhubarb crowns: Add your variety to Growli and the app schedules division windows, forcing dates, and the safe harvest cutoff in midsummer.

Variety selection

UK varieties

• Timperley Early (AGM) — the classic UK forcing variety. RHS Award of Garden Merit. First sold commercially in 1945, harvestable in early to mid-April naturally, and the best variety for forcing into February stems.
• Stein's Champagne (AGM) — slender deep-red stems, intense colour right through. Excellent for forcing. RHS AGM.
• Victoria — dating from 1837, the heritage British variety, dependable heavy crops with pink-and-green stems. Still widely sold.
• Stockbridge Arrow — developed in England in the 1960s, premium garden variety, strong long stems that hold colour and have outstanding sweet flavour. Distinctive arrow-shaped leaves.

US varieties

• Victoria — same heritage cultivar, widely grown across the US.
• Canada Red — deep red stalks, good cold-hardiness (USDA zones 3-8).
• Crimson Red / Crimson Cherry — long red stalks, sweet flavour, USDA zones 3-8.
• MacDonald — Canadian-bred, large stems with strong red colour, particularly tolerant of heavier soils.

Avoid seed-grown rhubarb unless you want a science experiment — seedlings are highly variable. Buy named crowns from a fruit specialist (Pomona Fruits, Blackmoor, Sarah Raven in the UK; Stark Bros, Nourse Farms, Burpee in the US).

Soil and site

Rhubarb wants:

• Full sun to partial shade — 4-6 hours minimum; tolerates more shade than most fruit crops.
• Deep, rich, well-drained soil — it's a heavy feeder with a big taproot.
• pH 6.0-6.8 (slightly acidic to neutral) — test using our soil pH guide.
• Plenty of organic matter — dig in a 5-7 cm (2-3 inch) layer of well-rotted manure or compost before planting.
• Permanent spot — once established, a rhubarb crown is hard to move. Pick the location carefully.

Avoid waterlogged ground (crowns rot) and very dry, shallow soils (yields collapse in summer).

When and how to plant

When

• UK: autumn (October-November) or early spring (February-March) while the crown is dormant.
• US: early spring as soon as the ground is workable, or autumn in zones 5-8.

Container-grown plants can go in any frost-free month.

How

1. Dig a hole 45 cm (18 inches) wide and 30 cm (12 inches) deep.
2. Mix in well-rotted manure or compost at 50/50 with the backfill.
3. Set the crown with the dormant bud (eye) just at or 2-3 cm above soil level. Bury it deeper and it rots.
4. Space crowns 90 cm (3 ft) apart in rows 120 cm (4 ft) apart.
5. Firm the soil and water in well.
6. Mulch with 5-7 cm of compost or well-rotted manure around the crown (but not on top of the bud).

The year-1 rule — don't harvest

The single most-broken rule in rhubarb growing. Do not pull any stalks in year one. A newly planted crown needs every leaf it produces to photosynthesise and build the deep root reserves that fuel decades of cropping. Harvesting in year 1 = a weak plant that takes 3 years to recover or never gets established.

In year 2, take a light harvest — 2-3 stalks per pull, every 2-3 weeks, for a 4-6 week window.

From year 3 onwards, harvest freely from late April / early May through to mid-July, taking no more than a third of the stalks at any time.

Forcing — for super-early UK stems

Forcing rhubarb in the dark produces tender, sweet, pale-pink stems 3-4 weeks before the main outdoor crop. It's a Yorkshire tradition — the famous "Rhubarb Triangle" between Wakefield, Morley, and Rothwell. You can do it at home with one of two methods:

Forcing in situ

1. In late winter (January-February in the UK), cover a strong, mature crown (year 3+) with a forcing pot, large bucket, or upturned dustbin. Block any holes to exclude light entirely.
2. Insulate around the cover with a thick mulch of straw or composted leaves.
3. After 4-5 weeks, stems will be 30-40 cm tall, pale pink, tender, and ready to harvest.
4. Force the same crown only once every 2-3 years — forcing exhausts the root reserves.

Lifting and forcing indoors

A Yorkshire commercial trick: dig up a mature crown in November, expose it to a hard frost for a week, then bring it into a dark warm shed (10-15°C) and water occasionally. Stems push up in 4-6 weeks, ready for harvest. Discard the crown afterwards — it's spent.

The RHS recommends forcing only mature, well-established crowns and giving them a full season's rest before forcing again.

Harvesting — pull, don't cut

The correct technique:

1. Grip the stalk near the base.
2. Twist gently while pulling outward and upward. The stalk separates cleanly at the crown.
3. Trim off the leaf at the top of the stalk and discard (compost, slug-mulch — see safety warning above; never feed to pets).
4. Take no more than a third of the stalks at any one time so the plant keeps photosynthesising.

Stop harvesting by mid-July in most climates — even from established mature plants. The leaves left from August onward feed the crown for next year's crop. Taking stalks too late weakens the plant.

Mature crowns produce 2.5-4.5 kg (5-10 lb) of stalks per season.

Feeding and watering

Feeding

• Top up the mulch each spring with a 5 cm (2 inch) layer of well-rotted manure or compost — this supplies most of the season's nutrients.
• Light feed in early summer with a high-potassium liquid feed (tomato food works) after the main pull.
• Avoid high-nitrogen feeds — they push leafy growth at the expense of root reserves.

Watering

• During dry spells, give a deep weekly soak (2.5-4 cm / 1-1.5 inches).
• Mulch deeply — rhubarb roots are big but most of the active feeding roots are in the top 30 cm.
• Don't water the crown directly — water the surrounding soil.

Flowering — cut it out

A mature rhubarb sends up a tall flowering stalk every few years, usually after stress (heat, drought, age). It looks impressive but diverts energy from the crown. Cut the flowering stalk off at the base as soon as you see it.

Repeated flowering is the plant telling you to divide or refresh.

Division — every 5-7 years

Crowns get congested over time, with smaller, thinner stalks and reduced vigour. Lift and divide every 5-7 years:

1. In late autumn (after the leaves have died back) or very early spring, dig up the entire crown.
2. Use a sharp spade or knife to cut into 3-4 pieces, each with at least one healthy dormant bud.
3. Replant the pieces in fresh soil 90 cm apart, with fresh compost dug in.
4. Don't harvest from divisions in their first replanted year — same as planting from scratch.

You'll have spare crowns — gift them to neighbours. A rhubarb crown is forever.

Pests and problems

• Crown rot — caused by waterlogging or buried buds. Lift, trim out the rotten section, and replant high. Prevention: well-drained soil and don't bury the bud.
• Slugs and snails — young shoots in spring. Use copper rings or wool pellets; rhubarb leaves themselves are an effective slug-deterrent mulch (the oxalates).
• Honey fungus — affects mature crowns in older gardens. No cure; replant in fresh ground if you lose a crown.
• Flowering repeatedly — sign of crown stress; divide.

Companion planting

Rhubarb pairs well with:

• Brassicas — the strong smell of rhubarb is said to confuse cabbage white butterflies (anecdotal but harmless).
• Strawberries — old cottage-garden combination; they like similar soil and complement each other in the kitchen.

Avoid planting close to legumes (peas, beans) — rhubarb is a heavy feeder that outcompetes them.

See our companion planting guide for more pairings.

Related articles

• How to grow strawberries — classic cottage-garden pairing
• How to grow blueberries — sibling soft-fruit guide
• Companion planting guide — rhubarb pairings
• Soil pH guide — target 6.0-6.8 for rhubarb
• Frost-date calculator — your local planting windows
• How to start a vegetable garden — bigger-picture beginner guide
• Garden pest identification — diagnosing crown rot and slugs

Reviewed and updated by the Growli editorial team. Founded by Justas Macys and Nojus Balčiūnas; published by YNMO LTD (UK Companies House #13293288). For questions about anything here, open Growli and ask — or email hello@getgrowli.app.