Bought in Floors sale 2010 £4 bargain. Label showed dark pink flowers but in fact they are a pale-ish blue so they are going against the pale shade where most of the other plants are white.

Double Flowered
Suitable for containers
RHS Award of Garden Merit

1. Position: full sun or partial shade
2. Soil: fertile, well-drained, neutral soil
3. Rate of growth: average
4. Flowering period: April to May
5. Flower colour: mid-blue
6. Other features: silvery seedheads
7. Hardiness: fully hardy

Large, double, bell-shaped, mid-blue early spring flowers followed by attractive, silvery, seedheads retained throughout the summer. This early spring-flowering clematis is ideal for covering a north-facing fence or wall. It also looks lovely trained to climb into small trees or allowed to scramble through neighbouring shrubs.

1. Garden care: No routine pruning is necessary. If the spread of the plant needs to be restricted prune immediately after flowering, cutting back overlong shoots to healthy buds. Apply a slow-release balanced fertiliser and a mulch of well-rotted garden compost around the base of the plant in early spring.
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   The following is edited from The Telegraph article on growing C. macropetala.
   http://www.telegraph.co.uk/gardening/3348412/Clematis-macropetala-How-to-grow.html

‘Wesselton’ is a fine AGM variety, with 2in flowers, composed of lavender blue sepals and paler lavender and white staminodes, 14 of which are slightly longer than the sepals, like a full petticoat. This is one of the earliest of the C. macropetala cultivars to flower and it grows up to 8ft.

Plant against trellis or wire netting, or next to a large, stout shrub, such as a species rose, a climbing rose or a small fruit tree. Wires on walls are not very satisfactory; you need netting or trellis; otherwise the clematis will hang like a cat’s cradle over the wire.

Clematis need to have their roots shaded and cool, since they are woodland plants, so put them where shrubs can shade their lower parts, or where flat stones can be laid to keep the sun off their roots.

The Atragene Group clematis are so winter-hardy, they can be planted facing north or north-east.

Clematis do best in an alkaline soil (with a pH above 7) and one that is moisture-retentive. They can be planted out of containers at most times of year, but it is inadvisable to plant them in the depths of winter or in summer, since they have such a continuous requirement for moisture.

Make a hole at least 18in square and deep, and at least 18in away from the wall or fence, put some well-rotted compost in the bottom and tread it down lightly.
Add a little soil, then knock the plant out of the container and plant it so that the crown is 2½in below ground level. (C. macropetala is not as prone to clematis wilt as the early, large-flowering clematis, but this is still thought to be good practice.) If you are planting against a wall or fence, lean the plant, still tied to its bamboo stake, against it at an angle.

Fill in round it with good soil, to which bonemeal has been added, and tread down lightly. Water in thoroughly, then lay slates or tiles round the stems. Cut the stems down, initially, to 12in. In future years, trim dead and weak growths if necessary after flowering.

In time, if the plant gets very woody, cut it back hard after flowering to encourage new young shoots.