Clematis 'Ken Donson' (EL)

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clematis 'Ken Donson'

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clematis 'Ken Donson' RHS
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Climber Wall Shrub

Grows to 2.5-3m, and has large, deep blue flowers with contrasting white filaments and bright yellow anthers making up the gold stamens. Flowers may be produced any time between June and September and followed by prominent seedheads

Position

Full sun, Partial shade

Soil Types

Clay, Loam, Sand

Max Height

2.5-4 metres

Max Spread

0.1-0.5 metres

Size

Time to Maturity
2–5 years
Max Spread
0.1-0.5 metres
Max Height
2.5-4 metres

Growing Conditions

Clay Loam Sand
Moisture
Moist but well–drained
pH
Acid or Alkaline or Neutral

Position

Full sun Partial shade
Aspect
South–facing or North–facing or West–facing or East–facing
Exposure
Sheltered
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 & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Ranunculaceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Climbing
Potentially harmful
Skin irritant. Wear gloves and other protective equipment when handling. Pets (rabbits): Harmful if eaten. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
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
Name Status
Accepted
Horticultural Group

Horticultural Classification Codes

Horticultural Classification Codes are often given to genera which have a large number of species or cultivars. They are used to categorise cultivated plants based on specific, shared characteristics such as shape, colour, size or flowering time, and can be displayed as letters or numbers

For example:
Dahlia ‘Sunset Kate (Sin) = Single flower
Rosa ‘Marigold’ (HT) = Hybrid Tea

Early Large-flowered clematis have large star-shaped flowers in early summer, often with a second flowering in late summer

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 for more advice

Propagation

Propagate by softwood cuttings in spring, semi-ripe cuttings in summer or propagate by layering in late winter or early spring

Suggested planting locations and garden types

  • City and courtyard gardens
  • Cottage and informal garden
  • Patio and container plants
  • Flower borders and beds
  • Wall side borders

Pruning

Clematis pruning: group two

Pests

May be susceptible to aphids, snails and caterpillars; petals may be eaten by earwigs

Diseases

May be susceptible to honey fungus (rarely), clematis wilt and clematis slime flux