• 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 tweedyi 'Alba'

lewisia 'Alba'

lewisia 'Alba'

© RHS 1999

  • Other common names lewisia 'Alba'

  • 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 'Alba' has a loose rosette of fleshy, spoon-shaped leaves and slender-stalked sprays of funnel-shaped white flowers to 6cm wide in spring and early summer on stems to 25cm long

Characteristics

  • Foliage Evergreen

  • Habit Mat 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)

    H4

Colour

Sunlight

  • Full Sun

  • Partial Shade

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

  • Exposure Sheltered or Exposed

Soil

  • Sand

    Sand

  • Loam

    Loam

  • MoistureWell-drained

  • SoilSand, Loam

  • pHNeutral, Acid

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 Grow in moderately fertile, humus-rich, sharply-drained, neutral to acid soil. Lewisias dislike winter wet. A position in light shade is ideal. Planting in a crevice or wall can provide all of these requirements

Propagation Propagate by seed in a seedbed as soon as ripe, or divide in early spring

Suggested planting locations and garden types Gravel Garden Rock Garden Patio & Container Plants

How to care

Pruning No pruning required

Pests slugs and snails can problematic

Diseases Neck rot can affect them in wet conditions

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