• 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

Tricyrtis formosana

toad lily

toad lily

© RHS

  • Other common names toad lily

  • Family Liliaceae

  • Genus Tricyrtis are rhizomatous perennials, sometimes stoloniferous, with erect or arching stems with alternate, sometimes 2-ranked leaves and star-shaped or bell-shaped flowers that may be solitary or in terminal or axillary clusters

  • Details T. formosana is a rhizomatous herbaceous perennial with erect stems to 80cm, with dark-spotted lance-shaped leaves and lax clusters of star-shaped whitish flowers 2.5cm in width, heavily spotted purple

  • Plant range Taiwan

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

  • Sand

    Sand

  • Loam

    Loam

  • Chalk

    Chalk

  • MoistureMoist but well-drained

  • SoilSand, Loam, Chalk

  • pHAcid, Neutral

Size

  • Ultimate height 0.5-1 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation Grow in moist but well-drained, humus-rich soil in deep or partial shade. In cold areas, a sheltered position encourages flowers before the first frosts. May need a deep winter mulch if cold but no snow cover

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

Suggested planting locations and garden types Flower borders and beds Underplanting of Roses and Shrubs

How to care

Pruning Remove faded flowerheads

Pests Slugs and snails may be a problem

Diseases Generally disease free

Advertise here

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