Clematis 'Alan Postill' (M)

RHS Plant Profile
clematis 'Alan Postill'

Save a plant

Where do you want to save Clematis 'Alan Postill' (M)?

Plants I own
Wishlist
Go to My Plants
Climber Wall Shrub

Very rare, with an interesting story to its eventual successful propagation, this decidous climber about 2m in height, with glossy, rich bronze to dark green leaves, and white flowers about 6cm across, flushed pink

Position

Full sun, Partial shade

Soil Types

Chalk, Loam, Sand

Max Height

1.5-2.5 metres

Max Spread

1.5-2.5 metres

Size

Time to Maturity
2–5 years
Max Spread
1.5-2.5 metres
Max Height
1.5-2.5 metres

Growing Conditions

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

Position

Full sun Partial shade
Aspect
South–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
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
Unresolved
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

Montana Group clematis are vigorous deciduous climbers with single, 4-petalled flowers opening in late spring and early summer

How to Grow

Cultivation

Plant in 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. Can be grown in containers at least 45cm deep and wide in a peat-free, loam-based potting compost. See clematis cultivation

Propagation

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

Suggested planting locations and garden types

  • City and courtyard gardens
  • Cottage and informal garden
  • Patio and container plants
  • Climber and wall shrubs
  • Wall side borders

Pruning

Pruning (Clematis) Group 1

Pests

Young shoots may be susceptible to aphids, slugs, snails or caterpillars

Diseases

May be susceptible to clematis wilt and clematis slime flux