• 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

Actaea racemosa

black snakeroot

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
black snakeroot

© � RHS 1999

  • Other common names black snakeroot
    bugbane

    black cohosh
    cohosh bugbane

    see more
  • Synonyms Cimicifuga racemosa
    Cimicifuga racemosa var. racemosa

  • Genus Actaea are rhizomatous herbaceous perennials with compound leaves and small creamy-white flowers in short, erect, simple or branched terminal racemes, followed either by poisonous red, black or white berries, or by star-shaped clustered brown follicles

  • Family Ranunculaceae / Ranunculaceae

  • Details A. racemosa is a perennial to 1.5m, with long, branched, bottlebrush-like racemes of small, white flowers carried well above the bright green, divided leaves, and followed by dry brown follicles

  • Plant range E North America

Characteristics

  • Foliage Deciduous

  • Habit Clump-forming

  • 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)
    Old hardiness ratings

    While we update our systems with the new hardiness ratings you may still see old hardiness ratings in your search results. These are denoted as 'Old'.

    • H1 - Requires heated glass
    • H2 - Requires unheated glass
    • H3 - Hardy outside in some regions of the UK
    • H4 - Hardy throughout the UK
    • H1 + H3 - Requires heated glass but may be grown outside in summer

    For full details of the hardiness ratings see

    see more

    H7

Colour

Sunlight

  • Partial Shade

  • Aspect East-facing or West-facing or North-facing

  • Exposure Sheltered

Soil

  • Chalk

    Clay

  • Chalk

    Loam

  • MoistureMoist but well-drained, Poorly-drained

  • SoilClay, Loam

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height

    1-1.5 metres

  • Ultimate spread

    0.1-0.5 metres

  • Time to ultimate height

    2-5 years

How to grow

Cultivation Grow in cool, moist, moderately fertile soil, enriched with organic matter. Water thoroughly in dry weather.

Propagation Propagate by seed sown in pots in a cold frame in autumn or by division in early spring

Suggested planting locations and garden types Flower borders and beds Cottage & Informal Garden Wildflower meadow

How to care

Pruning Cut back after flowering or fruiting

Pests Generally pest free

Diseases Generally disease free

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