• AGM plants

    AGM plants have been through a rigourous 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

Trillium rivale

Brook wakerobin

AGM plants

AGM plants have been through a rigourous 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
Brook wakerobin

© � RHS

  • Other common names Brook wakerobin

  • Synonyms Pseudotrillium rivale

  • Genus Trillium are rhizomatous, herbaceous perennials with erect stems bearing a whorl of ovate or diamond-shaped leaves, with one or more erect or nodding flowers borne at the stem apex

  • Family Melanthiaceae / Melanthiaceae

  • Species T. rivale is an herbaceous perennial to 12cm, the upright stems each bearing a whorl of three ovate leaves and a solitary terminal flower 3-4cm in width, with three ovate pinkish-white petals speckled purple near base

  • Plant range W United States

Characteristics

  • Foliage Deciduous

  • Habit Clump-forming

  • Toxicity

  • 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

    H4

Colour

Sunlight

  • Partial Shade

  • Full Shade

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

  • Exposure Sheltered

Soil

  • Chalk

    Chalk

  • Chalk

    Loam

  • Chalk

    Sand

  • MoistureMoist but well-drained

  • SoilChalk, Loam, Sand

  • pHAcid, Neutral

Size

  • Ultimate height

    Up to 10 cm

  • Ultimate spread

    0-0.1 metre

  • Time to ultimate height

    2-5 years

How to grow

Cultivation Grow in deep, moist but well-drained, humus-rich, preferably acid to neutral soil in deep or partial shade. Mulch in autumn with leaf mould

Propagation Propagate by seed, in pots in a shady cold frame as soon as seed is ripe; takes 5-7 years to reach flowering size. Propagate rhizomes by division after flowering or cut out the growing point from the rhizome after flowering, which stimulates the formation

Suggested planting locations and garden types Flower borders and beds Underplanting of Roses and Shrubs Cottage & Informal Garden Rock Garden

How to care

Pests Slugs and snails may be a problem

Diseases Generally disease free

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