• 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

Tiarella cordifolia

foam flower

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
foam flower

© RHS

  • Other common names foam flower
    coolwort

    false mitrewort
    white coolwort

    see more
  • Family Saxifragaceae

  • Genus Tiarella are rhizomatous herbaceous perennials forming a clump of rounded, more or less palmately lobed leaves, with very small, star-shaped flowers in terminal panicles or racemes on erect stems

  • Details T. cordifolia is a stoloniferous herbaceous perennial to 30cm in height, with 3 to 5-lobed, broadly ovate leaves becoming bronze-tinged in autumn, and erect stems bearing open racemes of small, creamy-white flowers

  • Plant range Eastern N 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)

    H5

Colour

Sunlight

  • Partial Shade

  • Full Shade

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

  • Exposure Sheltered

Soil

  • Clay

    Clay

  • Loam

    Loam

  • Chalk

    Chalk

  • MoistureMoist but well-drained, Poorly-drained

  • SoilClay, Loam, Chalk

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 0.1-0.5 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation Ideally grow in cool, moist, humus-rich soil in partial or full shade but can tolerate a wide range of soils and can spread freely. Protect from excessive winter wet

Propagation Propagate by seed in pots in a cold frame as soon as seed is ripe or in spring. Propagate by division in spring

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

How to care

Pruning Remove spent flowers and leaves as required

Pests Generally pest free

Diseases Generally disease free

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