The timing of pruning clematis depends upon when the particular cultivar flowers. Clematis bloom on either last season's growth or on new growth. Knowing the variety of the clematis is the key to the proper pruning time and the amount to be done. Remember: if in doubt, don't prune before flowering!
Most large-flowered clematis varieties bloom in the spring on old growth. These are pruned lightly in late winter or early spring. Start pruning from the top down, removing only dead and damaged stems to the highest pair of healthy buds. These may be only 2 or 3 feet above the ground, depending upon the age and vigor of the plant and its variety. Some popular clematis pruned in this way include Dr. Ruppel, Duchess of Edinburgh, Henryi, Elsa Spaeth, Nelly Moser, and General Sikorski.
Smaller-flowered summer or early fall blooming clematis flower on new growth. Prune them hard at the end of the growing season or in early spring. Start from the bottom and work upward from healthy pairs of buds located 15 to 30 inches above the ground. Remove all old top growth that didn't die naturally over the winter. Many plants will add eight or more feet of new growth during one season. Some popular clematis pruned in this way are Jackmanni, Niobe, Comtesse de Bouchaud, terniflora (Sweet Autumn), Hagley Hybrid, tangutica, texensis, and the viticellas, like Julia de Correvon and Polish Spirit.
When early bloomers are through blooming, deadhead the flowers if you want to encourage a second flowering, rather than enjoying the decorative seed heads. After pruning, be sure to water, fertilize, and mulch your clematis. Tie the stems securely to supports to prevent wind damage.
