• 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 'Walenburg' (Vt)

clematis 'Walenburg'

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 'Walenburg'

© RHS

  • Other common names clematis 'Walenburg'

  • 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

  • Horticultural Group Viticella Group are deciduous climbing shrubs with usually pinnate leaves, and nodding, single to double, open-bell-shaped flowers of small to medium-size, produced on the current year's growth in summer and early autumn

  • Details 'Walenburg' is a deciduous climber with yellow-green foliage growing to about 3m and blooming from early to late summer. The flowers open from a broad, hanging bell to an outward-facing star, and have four, deep velvety-red-purple sepals each with a broad, central, white stripe

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)

    H6

Colour

Sunlight

  • Full Sun

  • Partial Shade

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

  • Exposure Sheltered

Soil

  • Chalk

    Chalk

  • Clay

    Clay

  • Sand

    Sand

  • Loam

    Loam

  • MoistureMoist but well-drained

  • SoilChalk, Clay, Sand, Loam

  • pHAlkaline, Neutral, Acid

Size

  • Ultimate height 2.5-4 metres

  • Ultimate spread 0.5-1 metres

  • Time to ultimate height 2-5 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 new shoots to grow from below ground level. See clematis cultivation

Propagation Propagate by layering, softwood or semi-hardwood cuttings

Suggested planting locations and garden types Wall-side Borders Flower borders and beds City & Courtyard Gardens Cottage & Informal Garden Patio & Container Plants

How to care

Pruning Clematis pruning: group three

Pests Young shoots may be troubled by aphids and slugs; petals can be eaten by earwigs

Diseases May suffer from clematis slime flux. Likely to be tolerant of clematis wilt

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