We are often asked questions about pruning Clematis, and cultivars are often divided into groupings (1, 2 and 3) which are guides for optimal pruning.  Based on our own experience at Pleasant Run Nursery (and to simplify things), we have designated our Clematis into Group A and Group B.  

Group A:  Cultivars which benefit from a light pruning in late winter or early spring, followed by a light pruning after the summer bloom period.  The second pruning encourages the large flowered cultivars to rebloom in late summer.

Group B:  Species and Cultivars which tend to be more vigorous growers.  They preform best with a yearly hard pruning in late winter or early spring.  Always remove dead stems, and cut the Group B plants back to 1' to 2'.