Rhubarb

Rheum rhabarbarum · Vegetable

Quick answer: Water: Every 1–2 weeks, deeply (established); deep watering every 1–2 weeks once established. Light: Full sun, all day. Soil: Rich, well-drained, dug at least 2 ft deep. Pets: ASPCA lists rhubarb as toxic to cats and dogs, citing soluble calcium oxalates. Do not let pets chew the plant, and put trimmed leaves where pets cannot reach them. If in doubt, ask your vet.

A hardy perennial grown for its tart red or green stalks. Once established, one crown can give stalks every spring for 10–15 years or more. Only the stalks are eaten; the large leaves are not edible.

Care at a glance

Light

Full sun, all day

Water

Deep watering every 1–2 weeks once established

Soil

Rich, well-drained, dug at least 2 ft deep

Temperature

Hardy to USDA zone 4 (worth trying in zone 3)

Spacing

3 ft between plants, 4 ft between rows

Container

At least 20 gallons (estimated)

Harvest

From the third year; stalks 10–15 in long

Lifespan

10–15 years or more

When?

Plant crowns in early spring as soon as the soil can be worked. Do not harvest in the first two years; in the third year pick for 3–4 weeks, and from then on for 6–10 weeks each spring.

Step by step

1. Choose a permanent, sunny spot that drains well.
2. Mix 2–4 in of compost into the top 6 in of soil and clear perennial weeds.
3. Plant crowns with no more than 1 in of soil over the buds.
4. For the first 2–3 years, water once or twice a week, deep enough to wet the root zone.
5. Mulch to keep moisture in and weeds down.
6. Cut off flower stalks as soon as they appear.
7. Harvest by pulling and twisting the stalk; leave at least 1/3 of the stalks on the plant.
8. Divide crowns every 5–10 years in early spring, keeping a large bud on each piece.

Common problems

Pets

ASPCA lists rhubarb as toxic to cats and dogs, citing soluble calcium oxalates. Do not let pets chew the plant, and put trimmed leaves where pets cannot reach them. If in doubt, ask your vet.

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