When is the best time to harvest rhubarb?

Harvest stalks in spring and early summer when they are fully grown but still tender.

How do I harvest rhubarb stalks?

Gently pull or cut the stalks from the base, leaving the crown and smaller stalks to continue growing.

Why are my rhubarb leaves drooping?

Drooping can be due to insufficient water, extreme heat, or the plant preparing for dormancy.

Can rhubarb be grown from seed?

While possible, growing from seed is less common; division of established crowns is preferred for consistency.

Plant guide

Rhubarb.

Rheum rhabarbarum

Pronounced ROOM rab-BAR-bar-um

Also known as Garden Rhubarb, Pieplant, Rhubarb, pie-plant

Rhubarb is a perennial plant grown for its fleshy, tart-flavored leaf stalks, which are typically used in pies, jams, and desserts. While the stalks are edible, the leaves and roots are poisonous and should be avoided.

At a glance

Care level: Easy
Plant type: Herbaceous perennial
Light: Full sun to partial shade
Indoor light: direct
Water: Every 2 to 5 days
Mature size: Up to 1.5 meters tall and wide
Growth rate: medium
Hardiness: USDA 3 to 8
Bloom time: Late spring to early summer

Care

Grow rhubarb in a sunny spot with fertile, well-drained soil. Ensure consistent moisture, especially during dry spells. Remove flower stalks as they appear to direct energy into stalk production.

Watering: Keep soil consistently moist, especially in warm weather, but avoid waterlogging.
Feeding: Fertilize in early spring with compost or a balanced fertilizer after the ground thaws.
Pruning: Cut back dead foliage in late fall or early spring to tidy up and prevent disease.
Repotting: Divide clumps every 3-5 years in early spring or fall to rejuvenate the plant and control size.
Soil: Rich, moist, well-drained loam
Soil pH: Slightly acidic to neutral (6.0-7.0)
Temperature: -30 to 25°C
Humidity: 50 to 70%

Safety

People: High: Leaves and roots contain oxalic acid and are toxic if ingested.
Pets: High: Oxalic acid in leaves and roots can cause poisoning.
Edibility: Only the leaf stalks are edible; leaves and roots are toxic.

How to identify it

Large, basal leaves
Thick, fleshy leaf stalks
Small, greenish-white flowers
Grows in clumps
Rhizomatous root system

Height: 0.6 to 1.5m
Spread: 0.6 to 1.5m
Leaves: Green, Reddish-green, deciduous
Flowers: Greenish-white, 0.5 to 1cm

Common problems

Crown rot — Caused by excessive moisture, leading to root and crown decay.
Leaf spot — Fungal or bacterial infections causing spots on leaves.
Aphids — Small, sap-sucking insects that can infest new growth.
Slugs and snails — These mollusks can feed on the leaves and stalks.

Growing it

Propagation: Division, Seed
When to plant: Early spring, Fall

Plant rhubarb in an open area where it receives ample sun and has room to expand, and consider companion plants that can help improve soil fertility or deter pests.

Grows well with

Strawberries — Both thrive in similar conditions and benefit from the soil being slightly aerated by each other's root systems.
Mint — Mint can help deter some common rhubarb pests like aphids.
Beans — Legumes like beans fix nitrogen in the soil, benefiting nutrient-hungry rhubarb.

Keep away from

Brassicas (Cabbage, Broccoli) — Brassicas are heavy feeders and can compete with rhubarb for nutrients and water.

Similar species

Rhubarb Chard — Though often confused due to the 'rhubarb' in its name and colorful stalks, it is a type of Swiss chard, not true rhubarb, and is grown for its edible leaves and stalks which are milder.

Science

Family: Polygonaceae
Genus: Rheum
Order: Caryophyllales
Class: Magnoliopsida
Native range: Siberia and Western China

In its native, cold regions, rhubarb survives harsh winters with dormant roots and emerges in spring with new growth fueled by stored energy.

Uses: Culinary (stalks), Ornamental

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 1/9
Soil reaction: 5/9
Light: 8/9
Temperature: 2/9
Moisture: 6/9
Nutrients: 7/9

Taxonomy resolved against GBIF.

Questions people ask

When is the best time to harvest rhubarb?: Harvest stalks in spring and early summer when they are fully grown but still tender.
How do I harvest rhubarb stalks?: Gently pull or cut the stalks from the base, leaving the crown and smaller stalks to continue growing.
Why are my rhubarb leaves drooping?: Drooping can be due to insufficient water, extreme heat, or the plant preparing for dormancy.
Can rhubarb be grown from seed?: While possible, growing from seed is less common; division of established crowns is preferred for consistency.

Where the name comes from

The scientific name 'Rheum' comes from the Greek 'rheion', meaning 'flow', referring to its medicinal use to treat various ailments. 'Rhabarbarum' is thought to derive from 'Rha', the ancient name for the Volga River, indicating its origin from barbarous lands.

Good to know

It's botanically classified as a vegetable but often used in desserts like a fruit.
Rhubarb stalks can be red, green, or a mix of both colors.
The plant has a long lifespan and can produce for 10-20 years.

Is your rhubarb looking unwell?

This page is a general guide. Pocket Botanist diagnoses problems from a photo of your actual plant, works out watering for your light and conditions, and reminds you when care is due.

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This guide was generated with AI and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.