Group 1 (Spring Bloomers):
These clematis flower only once in the spring, typically on old wood. They don't need much pruning, just a tidy after flowering.
Group 2 (Repeat Bloomers):
These clematis bloom twice a year: once in spring on old wood and again in summer or fall on new wood. Pruning is often done in early spring to maintain the bloom.
Group 3 (Summer/Fall Bloomers):
These clematis bloom exclusively on new growth, usually in late summer or fall. They are often cut back hard after flowering to promote fresh growth.