• 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 montana

mountain clematis

mountain clematis

© RHS

  • Other common names mountain clematis
    Himalayan clematis

  • 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 seedheads in autumn

  • Details C. montana is a vigorous deciduous species, reaching 7-12m if left unchecked. Plants are smothered in small, single, white flowers in late spring; leaves often have a bronze or purple hue when they first emerge before turning green

  • Plant range Him., China, Tibet

Characteristics

  • Foliage Deciduous

  • 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)

    H5

Colour

Sunlight

  • Full Sun

  • Partial Shade

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

  • Exposure Sheltered or Exposed

Soil

  • Chalk

    Chalk

  • Clay

    Clay

  • Sand

    Sand

  • Loam

    Loam

  • MoistureMoist but well-drained

  • SoilChalk, Clay, Sand, Loam

  • pHAlkaline, Neutral

Size

  • Ultimate height 8-12 metres

  • Ultimate spread 2.5-4 metres

  • Time to ultimate height 5-10 years

How to grow

Cultivation Plant in a moisture-retentive, well-drained soil, with the roots and base of the plant kept cool and shaded by other plants or a layer of pebbles at the base. Plant with the crown 5-8cm deep to encourage shoots to grow from below ground level. Good for scrambling up trees in a naturalistic setting. See clematis cultivation

Propagation Propagate by layering or semi-hardwood cuttings

Suggested planting locations and garden types Wall-side Borders Cottage & Informal Garden

How to care

Pruning Flowers on previous season's growth. Pruning (clematis) group 1

Pests Young shoots may be troubled by aphids

Diseases May suffer from powdery mildews, clematis slime flux or clematis wilt

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