Pruning techniques for Clematis can be varied. We've broken the many varieties into three different groups with our recommended pruning tactics.
This group produces flowers directly from old stems, therefore pruning must not be done until after all flowering has been completed. Remove all dead and weak stems immediately after flowering and then prune to size. Large established plants over 15 feet don't need to be pruned unless it has outgrown its space. New growth will begin at this time as the plant gets ready for next season's flowers.
Varieties: Asao, Blue Dancer, Grandiflora, Helsingborg, montana Grandiflora, montana Rubens, Multi Blue
All flowering for this group comes from last season's ripened stems. In early spring watch for swelling leaf buds and then cut all dead material off above the swelling buds. Be sure all growth is tied to trellis at this time, but do not tie too tightly.
Varieties: Arctic Queen, Barbara Jackman, Bees Jubilee, Belle of Working, Blue Moon, Blue Ravine, Dr. Ruppel, Duchess of Edinburgh, Elsa Spath, Ernest Markham, General Sikorski, Gillian Blades, H.F. Young, Hagley Hybrid, Henryii, Jackmanii, James Mason, Marie Boisselot, Miss Bateman, Mrs. N. Thompson, Nelly Moser, Pink Champagne, Ramona, Scartho Gem, Sugar Candy, The President, Ville de Lyon, Vyvyan Pennel, Westerplate, Will Goodwin
This group blooms later and from new growth. Prune in February or March as new leaf buds begin to show low on the plant. All dead material above these buds should be removed at this time. Clean out any old foliage or foliage with mildew at this time also.
Varieties: Ascotiensis, Betty Corning, Comtesse de Bouchard, Cote d'Azur, Etoile Violette, Golden Harvest, Helios, integrifolia, Jackmanii Superba, Lady Betty Balfour, Mrs. Cholmondeley, Mrs. Robert Brydon, My Angel, Niobe, paniculata, Pearl d'Azur, Pink Fantasy, Polish Spirit, Radar Love, recta Purpurea, Rouge Cardinale, Venosa Violacea, Warsaw Nike