Clematis

Clematis are a genus of more than 300 species, with more wild species of clematis than of roses. They are invaluable in the garden, generally trained as climbers on walls or fences, allowed to scramble through trees and shrubs, or even to trail along the ground. There are some smaller varieties which are happy to grow in a container so there’s one for every situation. In theory it’s possible to have a clematis in flower every month of the year. Most will survive in full sun or partial shade, but check individual varieties for the situation you are working with.

Planting Clematis: Plant in moisture retentive, but well drained, soil. Keep the base of the plant and roots cool, by careful positioning of other plants, or with a layer of stones or pebbles. Install wires or trellis for the plant to grow up, tying in new growth with soft ties or clips.

Pruning Clematis: Clematis are often grouped according to their pruning requirements into 3 groups. Some clematis flower on the previous year’s wood, and some on shoots produced in the same year. Knowing when your clematis flowers will help you determine which group it belongs to if you don’t know.

Pruning group 1 - early flowering clematis e.g. Clematis alpina, Clematis montana, Clematis armandii, Clematis cartmannii and their cultivars.

Prune immediately after flowering, if needed. Remove damaged stems and reduce congestion to ensure it remains within the available space. To renovate, the plant can be cut right back to within 30cm of the ground, above a pair of buds. Flowering may be affected the following year but response is normally good. Feed and mulch and keep watered in dry spells.

Pruning group 2 - large flowered clematis e.g. Clematis Nelly Moser, Bees Jubilee, Snow Queen, The President, Royal Velvet and many more. These flower in early summer, May and June, on short stems which develop from the previous years growth. Some flower again in late summer on new growth.

Plant group 2 clematis with the top of the rootball 5-8cm below the surface.

Newly planted clematis should be pruned hard, to 30cm from the ground, in the first spring after planting to encourage a network of flowering stems. Tie in new stems to wires or supports. In subsequent years, prune weak and dead stems before growth starts. Cut back lightly to a strong bud after the first flowering, or to a strong shoot below a flower to encourage a second flush of flowers.

Pruning group 3 - later flowering clematis e.g. Clematis Gypsy Queen, Jackmanii, Perle D’Azur. These flower in mid to late summer on the current season’s growth.

Prune to just above a strong pair of leaf buds, 30cm from the ground in late winter/early spring, typically February. If left unpruned, these Clematis will carry on growing from the previous years growth, with a bare base and an unruly mass at the top. They can, however, be left unpruned and allowed to scramble into trees or over pergolas where space is fairly unlimited.