• 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

Lysimachia ephemerum

willow-leaved loosestrife

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
willow-leaved loosestrife

© RHS

  • Other common names willow-leaved loosestrife

  • Family Primulaceae

  • Genus Lysimachia are herbaceous or evergreen perennials with simple leaves and star-shaped, cupped or bowl-shaped flowers in terminal racemes or panicles, or solitary in leaf axils

  • Details L. ephemerum is an herbaceous perennial forming a clump of erect stems clad in narrow, grey-green leaves, with small, starry white flowers in long, slender terminal racemes in early summer

  • Plant range S W Europe

Characteristics

  • Foliage Deciduous

  • Habit Bushy

  • 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)

    H6

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or West-facing

  • Exposure Exposed or Sheltered

Soil

  • Clay

    Clay

  • Loam

    Loam

  • MoistureMoist but well-drained, Poorly-drained

  • SoilClay, Loam

  • pHAcid, Alkaline, 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 humus-rich, preferably moist but well-drained soil that does not dry out in summer, in full sun or part shade

Propagation Propagate by seed in containers outdoors in spring. Divide in spring or autumn

Suggested planting locations and garden types Flower borders and beds City & Courtyard Gardens Coastal Cottage & Informal Garden

How to care

Pruning Tidy after flowering and cut down dead foliage in late winter or early spring

Pests May be damaged by slugs and snails

Diseases Generally trouble free

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