Clematis pruning is important for two reasons. Firstly, pruning in the years after planting will produce a better clematis in the years to come. Secondly, pruning is important in the case of group 2 and 3 clematis, which only produce flowers on new wood. By following these steps, you can ensure showstopper blooms.
Once planted, clematis will need pruning to encourage the development of six to eight sturdy stems, which is known as branching. This will produce a better looking clematis in the years to come just like the formative pruning of a young tree. Otherwise, clematis tend to produce very long stems with flowers at the very top.
Similar to roses, some clematis only produce flowers on new wood, and will need thinning to encourage the formation of new growth. Avoiding pruning will produce top heavy blooms, way above eye level.
Clematis Flowering Groups
Clematis are divided into four groups: 1, 2, 3 and herbaceous. Group 1 flower in mid-to-late spring, usually after the last frost. Group 2 flower in May-June and again in Sept-Oct, although some varieties flower continuously from June till Autumn. Group 3 and herbaceous clematis flower from late June and October.
Thus you can tell your clematis by when it flowers and whether it produces on old wood. Herbaceous clematis is distinct as it does not produce wood at all.
When pruning cut just above a pair of leaf buds, which will produce new stems.
In the first year after planting in February, cut down to about 30cm to encourage branching.
With herbaceous clematis, cut down to 15cm; you’ll need to do this in every subsequent year.
In the second year, cut down to about 100cm to encourage branching at this level. Do this for group 1 after flowering (after spring), and group 2 in February.
With group 3 cut down to 45cm to encourage branching at this level.
In the subsequent years, group 1 needs minimal maintenance. Simply remove dead or weak stems and trim to confines of available space.
With group 2, again tidy up, and cut back all stems to a strong pair of buds come February. Don’t prune too heavily or it may not flower.
You can prune again after the first flush of flowers to simulate a second flush of flowers. Simply cut back to large buds or a strong side shoot immediately below the blooms.
With group 3, start at the bottom of the plant and work your way up till you reach the first good pair of buds. Cut right above it and repeat for every stem. Pruning back to between 45-75cm is ideal as it ensures flowering is at eye level.
So, in summary, group 1 requires minimal maintenance, group 2 needs to be reduced and group 3 needs to be heavily cut back.
Pruning Established Plants
With groups 1-3, you can cut back to the lowest pair of healthy buds to produce a better structure. Some plants may take years to recover from severe pruning, and this repeated can kill a plant.
Jorge works in the Primrose marketing team. He is an avid reader, although struggles to stick to one topic!
His ideal afternoon would involve a long walk, before settling down for scones.
Jorge is a journeyman gardener with experience in growing crops.