• 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

Lewisia brachycalyx

short-sepal bitter-root

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
short-sepal bitter-root

© RHS

  • Other common names short-sepal bitter-root

  • Family Portulacaceae

  • Genus Lewisia can be herbaceous or evergreen perennials forming rosettes of fleshy leaves, with panicles of open funnel-shaped flowers in a wide range of colours in spring and summer

  • Details L. brachycalyx is a deciduous, tufted perennial to 8cm in height, forming a rosette of narrow fleshy dark green leaves, with solitary white or pale pink flowers 3-5cm in width, borne just above the foliage

  • Plant range SW USA

Characteristics

  • Foliage Deciduous

  • Habit Tufted

  • 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)

    H4

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or East-facing

  • Exposure Exposed

Soil

  • Loam

    Loam

  • Sand

    Sand

  • MoistureWell-drained

  • SoilLoam, 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 moderately fertile, humus-rich, very well-drained, neutral to acid soil in full sun; a gravel top-dressing helps to keep foliage dry. Protect from winter wet; dies down in summer when it needs protecting from rain because it is dormant. Suitable for cultivation in a container in an alpine house

Propagation Propagate by seed sown in pots in a cold frame in autumn

Suggested planting locations and garden types Wall-side Borders Gravel Garden Rock Garden Patio & Container Plants

How to care

Pruning Deadhead after flowering

Pests Prone to aphids under glass and to slugs and snails outdoors

Diseases Prone to neck rot in wet conditions

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