• AGM plants

    AGM plants have been through a rigorous trial and assessment programme. They are:

    • Excellent for ordinary use in appropriate conditions
    • Available to buy
    • Of good constitution
    • Essentially stable in form & colour
    • Reasonably resistant to pests & diseases

Rheum × hybridum

garden rhubarb

garden rhubarb

© RHS

  • Other common names garden rhubarb
    pie plant

  • Synonyms Rheum × cultorum

  • Family Polygonaceae

  • Genus Rheum are robust rhizomatous herbaceous perennials with large, simple or palmately lobed leaves and tall leafy stems bearing large panicles of tiny flowers

  • Details R. × hybridum is an herbaceous perennial which develops from a short crown, producing thick, angular stems and somewhat triangular leaves. The edible stems are 30-40cm in length and change from a light pink to red and finally green as they develop and age

Characteristics

  • Foliage Deciduous

  • Habit Bushy

  • Toxicity Leaves mildly toxic if ingested

  • Hardiness

    Hardiness ratings

    All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

    • H1a - Under glass all year (>15C)
    • H1b - Can be grown outside in the summer (10 - 15)
    • H1c - Can be grown outside in the summer (5 - 10)
    • H2 - Tolerant of low temperatures, but not surviving being frozen (1 to 5)
    • H3 - Hardy in coastal and relatively mild parts of the UK (-5 to 1)
    • H4 - Hardy through most of the UK (-10 to -5)
    • H5 - Hardy in most places throughout the UK even in severe winters (-15 to -10)
    • H6 - Hardy in all of UK and northern Europe (-20 to -15)
    • H7 - Hardy in the severest European continental climates (< -20)

    H5

Colour

Sunlight

  • Full Sun

  • Aspect South-facing

  • Exposure Sheltered

Soil

  • Sand

    Sand

  • Clay

    Clay

  • Chalk

    Chalk

  • Loam

    Loam

  • MoistureMoist but well-drained

  • SoilSand, Clay, Chalk, Loam

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 1-1.5 metres

  • Ultimate spread 1-1.5 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation Any fertile garden soil can be used for rhubarb as long as it is well-drained and in full sun. Crowns ("sets") can be cropped for ten or more years, though division may be necessary after about five years. Plant crowns in November or December and up to the beginning of March if necessary. A spring mulch of well-rotted organic matter 7cm (2 1/2in) deep will help to retain moisture but do not bury the crowns. Plants will also respond to watering during prolonged dry periods in summer. Apply a general fertiliser in spring or summer . See also rhubarb cultivation

Propagation Lift crowns between autumn and early spring (usually in November). Use a spade to divide the crown into sections each retaining a portion of the rhizome (thickened root) and at least one growing point. Sections from the outer part are better than the centres of old plants. Discard any old or decayed parts of the crown. Replant straight away or wrap in damp sacking until ready to plant

Suggested planting locations and garden types Low Maintenance Patio & Container Plants

How to care

Pruning Remove any flowerheads that may develop. Allow the foliage to die back naturally in autumn then cut away the old leaves to expose the growing points to winter cold

Pests Aphids, slugs and snails may be problematic

Diseases Honey fungus and a virus may be troublesome

Did you find the information you were looking for?

RHS members can get exclusive individual advice from the RHS Gardening Advice team.

Join the RHS now

Get involved

We're a UK charity established to share the best in gardening. We want to enrich everyone's life through plants, and make the UK a greener and more beautiful place.