How to Prune Clematis for Optimum Blooms

Credit: Clearview Hort

While severe pruning will not kill your clematis and can sometimes revitalize a neglected plant, it will delay flowering.

Every clematis should be cut back hard the very first early spring after planting (when you see leaf buds developing as your plant breaks dormancy, leave two sets of buds on each stem between your cut and soil level); following that it should be pruned according to its grouping:

GROUP A clematis flower only on growth from previous years. Prune to cut out weak or dead stems as soon as they are finished blooming in May or June. Pruning later than June or very severely will result in fewer blooms the following spring.
 

GROUP B1 produces a heavy flush of flowers May to June on the previous year’s growth followed by a smaller flush of blooms in September on new growth. A light pruning in late February or March with variation in the length of the stems will produce a well-balanced plant.

GROUP B2 blooms continuously from June to September on both last year’s and current growth. For pruning purposes these varieties can be treated as group B1 or C and because of that work well in combination plantings with both these groups.

GROUP C  blooms only on the current year’s growth, from early summer through to fall. Cut back plants in late February or March to two strong sets of buds on each stem as close to ground level as possible. If you want to grow a group-C clematis through a tree or have it flower above its normal blooming height, leave it unpruned.