Type

Fruit · Perennial

Botanical family

Mixed / other

Foliage color

Green

Flower color

Red

Sunlight

Full sun to part shade

Watering

Moderate–high

Soil

Deep, rich, moist

Feeding

A heavy mulch of manure in late winter.

USDA zones

3a–8a

Frost tolerant

Yes

Pruning

Take out the flower stalks as soon as they show, and clear the spent leaves in autumn.

Plant out

at the last spring frost

First harvest

30 days after the last spring frost

Harvest ends

90 days before the first fall frost

• Mar–Apr Spring Growth
• Apr–Jul Harvest
• Jul–Oct Growing
• Oct–Dec Leaf Fall
• Jan–Mar Leaf Fall

Plant spacing

2 ft 11 in

In-row spacing

2 ft 7 in

Between rows

3 ft 3 in

Square-foot density

Not suited to SFG

Root system

A fleshy crown with thick perennial roots

Working depth

18 in–4 ft

Can reach

5 ft down where the soil allows

Spread

3.5–5 ft across, about 1–1.5× the width of the plant

Shallowest pot

18 in of soil

The crown is the plant’s bank account and it is slow to rebuild, which is why a new planting is left unpicked for a season or two. Plant it at the depth it asks for and no deeper; these rot from being buried far more often than they suffer from being shallow.

A thick fleshy crown over roots that go down a long way, which is why an established plant is unmoved for a decade and why the one time to move it is winter, when the crown is dormant. Set the buds level with the surface: buried, they rot.

Figures recorded for Rhubarb itself. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.

Recorded as toxic to cats and dogs by ASPCA.

The source prints the epithet as rhabarbarium where we have rhabarbarum; the same plant. The hazard is the leaf blade, not the stalk people eat, which is the sort of distinction a one-word verdict cannot carry and this note can.

More about plants and pets

When

April to midsummer (forced stems as early as February). Do not harvest at all in the first year after planting; take a light picking in year 2 and full harvests from year 3. Stop pulling by late June/early July so the crown can rebuild — later stems are also stringy and higher in oxalic acid.

What to look for

Stems 25–45cm long, thick as a finger or better, with the leaf fully opened. Color is variety-dependent, not a ripeness cue — some are green when perfect. Thin, weak stems mean the crown needs a rest.

How to harvest

Pull, don't cut: grip low, twist and pull sideways so the stem comes cleanly from the base — cut stumps rot back into the crown. Take no more than a third to half of the stems at any pick. Cut off and compost the leaves immediately: they are toxic (oxalic acid) and must never be eaten.

How often

Every week or two through spring; the plant re-sends stems continuously until you stop at midsummer.

Storing the crop

Stems keep a week or two in the fridge (stand in a little water or bag loosely). Chops and freezes raw with no blanching needed. Classic for crumbles, compote, jam, and cordial. Remember: only the stalks are edible.

• Slugs & snails Slugs on the young shoots as they unfurl
• Honey fungus A fatal root disease of woody plants: white fungal sheets under the bark and honey-colored toadstools at the base. Remove the plant with as much root and stump as possible.
• Root & crown rot Crown rot

Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. ★ companion plant

• Beneficial nematodes Steinernema & Heterorhabditis spp.
  Hunts Slugs & snails

  Microscopic worms watered onto damp soil that hunt down soil-dwelling grubs and release a bacterium that kills them within days. Timing is the whole thing: warm, damp soil and a small target grub, which means late summer for most of what they are used against.

• Centipedes Chilopoda
  Hunts Slugs & snails

  Flat, fast, one pair of legs to a segment — and a predator, unlike the slow round millipede it is constantly confused with. It hunts slugs, cutworms, springtails and woodlice by night under mulch and stones. Learn the difference and leave this one alone.

• Frogs & toads Anura
  Hunts Slugs & snails

  A resident toad works the beds every night for slugs, cutworms, and weevils. Recruit them with water — even a sunken basin pond — plus damp shade and an upturned-pot toad house; skip the slug pellets that poison their prey.

• Garden birds Passeriformes
  Hunts Slugs & snails

  Both things are true: birds strip your currants and a brood of blue tits takes several thousand caterpillars out of one fruit tree in a fortnight. Net what you must and welcome them everywhere else — a nest box near the apples is worth more than a spray.

  Plant nearby EchinaceaElderberryEnglish hollyGoldenrodRudbeckiaSunflowerTeaselViburnum
• Ground beetle Carabidae
  Hunts Slugs & snails

  Fast, glossy night hunters that patrol the soil surface for slugs, cutworms, and root-fly larvae. Give them daytime cover — thick perennial edges, stepping stones, a log — and skip the tillage that wrecks their burrows.

  Plant nearby LavenderMintThyme
• Hedgehog Erinaceus europaeus
  Hunts Slugs & snails

  A European animal, and worth saying so plainly: there are no hedgehogs in North America, and the ally that does the same night shift here is the toad, the opossum or the ground beetle. Where they do occur, cut a gap in the fence and skip the pellets.

• Rove beetle Staphylinidae
  Hunts Slugs & snails

  Slim, quick beetles with short wing cases that hunt in soil and litter, taking root-fly eggs and larvae, fungus-gnat larvae, and mites. Mulch and undisturbed ground keep them resident year-round.

  Plant nearby MintThyme
• Salamanders & newts Caudata
  Hunts Slugs & snails

  Damp-loving hunters of slugs, worms, woodlice and beetle larvae that spend the day under a log or a stone and work the beds at night. Companions to the toads: they want the same damp shade, the same log pile, and the same absence of slug pellets.

• Snakes & lizards Colubridae & Phrynosomatidae
  Hunts Slugs & snails

  A garter snake works the beds for slugs and voles and a fence lizard clears grasshoppers off a sunny wall. Almost every snake a gardener meets is harmless and useful; give them a log pile, a warm flat stone and a bit of cover and they stay.

Garlic, Onions, Beans

Good neighbors

• Cabbage Repels pests