• 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

Clematis × cartmanii 'Avalanche' (PBR) (Fo/m)

clematis 'Avalanche'

clematis 'Avalanche'

© RHS

  • Other common names clematis 'Avalanche'

  • Synonyms Clematis AVALANCHE 'Blaaval'
    Clematis × cartmanii hort. 'Blaaval'

    Clematis 'Blaaval'

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  • Family Ranunculaceae

  • Genus Clematis can be deciduous or evergreen shrubs or herbaceous perennials, mostly climbing by twining leaf-stalks, and often with showy flowers. Some have attractive fluffy seed-heads in autumn

  • Horticultural Group Forsteri Group clematis are dwarf spreading or prostrate evergreen shrubs, usually dioecious, with deeply cut, trifoliate leaves and small cream or white, sometimes fragrant, flowers

  • Details 'Avalanche' is a bushy trailing or scrambling evergreen non clinging climber to a maximum height of 3m, with deeply dissected glossy, leathery, deep-green leaves. Panicles of pure white flowers to 4cm across, in early to mid spring

Characteristics

  • Foliage Evergreen

  • Habit Climbing

  • 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 East-facing or North-facing

  • Exposure Sheltered or Exposed

Soil

  • Chalk

    Sand

  • Chalk

    Clay

  • Chalk

    Chalk

  • Chalk

    Loam

  • MoistureMoist but well-drained

  • SoilSand, Clay, Chalk, Loam

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 1.5-2.5 metres / 2.5-4 metres

  • Ultimate spread 1.5-2.5 metres

  • Time to ultimate height 5-10 years

How to grow

Cultivation Prefers well-drained gritty soil in full sun or part shade with shelter. Plant with the crown 5-8cm (2-3in) deep to encourage shoots to grow from below ground level. Can be grown in a container in a cold greenhouse or conservtory

Propagation Propagate by layering or semi-hardwood cuttings

Suggested planting locations and garden types Flower borders and beds City & Courtyard Gardens Cottage & Informal Garden Gravel Garden Patio & Container Plants Rock Garden

How to care

Pruning Clematis pruning: group one

Pests Young plants may be troubled by aphids

Diseases Clematis wilt and clematis slime flux may be a problem

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