HOW TO PRUNE A CLEMATIS
The first spring after planting, all clematis should be cut back to two strong sets of buds for each stem. They then should be pruned according to category:
Pruning Group A - Flowers on growth produced in the previous year
Restrict pruning to cutting out weak or dead stems as soon as they finish blooming
Examples: Montana, Alpina, Macropetala
Pruning Group B - Plants that bloom on the previous season's growth, as well as those that flower on old and current wood
Both prefer a light pruning in early spring with some variation in the length of the stems
Examples: Duchess of Edinburgh, Countess Lavelase Pruning Group C - Blooms on the current year's growth
Cut back in early spring to two strong sets of buds on each stem
Examples: Jackmanii, Hugley Hybria, Ernest Markham | 
