How should I prune my clematis vines?

Question:

How should I prune my clematis vines?

Answer:

Clematis varieties can be placed into three groups based on their flowering characteristics. 

• Bloom on the current season’s growth.  These varieties tend to produce one flush of blooms sometime between late May and September.  They are some of the most common types found in Iowa.  (Examples: Clematis viticella, Clematis terniflora, and large-flowered hybrids such as Clematis × jackmanii, ‘Ernest Markham’, and ‘Hagley Hybrid’)
• Bloom on the previous year’s growth referred to as old wood. These varieties are the earliest to bloom in Iowa often flowering in May. (Examples: Clematis alpina and Clematis macropetala)
• Bloom on both old and new wood.  These varieties bloom twice each season. Large flowers appear between May and July and a second flush of smaller flowers happens in late summer. (Examples: ‘The President', ‘Henryi’, and ‘Ramona’)

Prune clematis vines that bloom on the current season's growth back to within 6 to 12 inches of the ground in late winter/early spring. 

Wait until the vines begin to leaf out before pruning the other two groups of clematis.  Prune out all the dead wood once the vines begin to leaf out.  Clematis vines of the last 2 groups will bloom poorly if much of the old growth is destroyed in winter. 

Learn more in this article: Growing Clematis in Iowa.