There are three different pruning types for clematis, depending on the where the flower buds form. Buds that grow on old wood will form in the fall. Buds that grow on new wood will emerge with the new spring growth. There are some varieties that produce buds on both old and new wood. Incorrect pruning rarely damages Clematis, the worst that can happen is loss of flowers for a year. But for the best display of blossoms, determine when your clematis blooms, and prune accordingly:
Group 1: “Old Wood”
Charmaine, Chevalier, Empress, Piilu
These are typically the varieties that are the earliest to flower in the spring. This group doesn’t need a lot of pruning, just trim lightly to remove and dead stems. It’s ok to take old, tangled plants down to the base of the wood to rejuvenate them. Do this just after flowering finishes in the spring so the plants have time to regrow during the summer.
Group Two: “Old & New Wood”
Cherokee, Diamantina, Franziska Maria, Nelly Moser, Multiblue, Rebecca, Rouge Cardinal, Samaritan Jo, Toki, Vancouver Starry Nights
These varieties usually flower profusely in the spring, followed by rebloom in late summer or fall. Lightly prune weak or dead stems back to a healthy set of buds, clearing out tangles after the spring flush of flowers is done. Old, tangled plants can occasionally be cut back by a third or more to reinvigorate the plant, but doing this will compromise the flowering in the next season. Large and double flowers will bloom on older wood.
Group 3: “New Wood”
Cassis, Edda, Endellion, Ernest Markham, Etoile Rose, Etiole Violette, Jackmanii, Kitty, Nubia, Sally, Sweet Autumn, Sweet Summer Love, Volunteer
These Clematis are usually summer or fall bloomers. Cut these varieties down to 8-12” from the ground in late winter. New shoots will emerge from the crown of the plant in the spring, loaded with flower buds.