Clematis

Zone: 3-9

Size: A rapid, vigorously growing vine climbing by using aerial roots and twining. Grows to 30-40 feet.

Location: Prefers full sun to part shade location. A site that gets 4-5 hours of sun a day is suggested. The soil should be well-drained and amended with ample amounts of organic matter. Prepare a planting site that is 18” X 18” X 18” in size and work in ample amounts of organic matter such as compost.

Flowering: large compound green leaves that look almost tropical. Flowers are orange-scarlet, 3 inches long, tube-shaped and showy from July-September. Attractive to hummingbirds and butterflies. After flowering, long, bean-shaped pods are produced that often persist through the winter. Trumpet vine may not flower for several years after planting until it becomes well established in the garden.

Maintenance: The success with clematis starts with picking the right location, preparing the planting site, proper planting, and proper pruning. Plants should be planted lower than they are growing in the container. It is suggested that the plants be set so the first two sets of leaf nodes are underground. This will encourage the plant to send up more stems resulting in a denser plant. Newly planted clematis should be pruned back to 12 inches in the spring following planting. Again, this will encourage a denser, fuller plant. Apply a 2-4 inch layer of mulch around the plant keeping it about 4-6 inches from the stem. This helps maintain cool soil temperatures that clematis prefers for best root growth. Pruning clematis has always seemed to be a mystery. It is based upon the blooming period for the variety.

Cultivars: Clematis are divided into three pruning groups designated as groups A, B, and C or sometimes 1, 2, and 3. Every clematis is put into one of these groups. Because you need to know the name of the clematis you have in order to prune correctly, you need to make sure you save the plant label that comes with the plant and somehow keep it with the plant or record the name of the clematis in your garden diary.

Group A clematis produce flowers from the mature growth that was produced last season. Light pruning to remove any dead stems and to neaten up the plant is all that is needed. Allow the plants to finish blooming in spring before you do any heavy pruning. This will put pruning into late spring or very early summer. This will allow enough time for the plant to produce new growth that will flower next season.

Group B clematis produce flowers on both old and new growth. The first flush of bloom is in early June with a repeat later in the season. Clematis in this group don’t need major pruning. When you do prune go slowly. Prune dead or weak growth and then lightly prune after the early flush of bloom. This helps to maximize blooming later in the year.

Group C clematis tolerate the most severe pruning as they produce flowers on the current seasons growth and tend to flower mid to late summer or very early fall. Many of these clematis benefit from very severe pruning in the spring. Cut back to 8-12 inches removing the tangled mass of stems produced last season. Doing this cleans up the plant and allows for many more vigorous shoots resulting in a fuller, cleaner plant covered with flowers.

Because of the extremely large numbers of good clematis varieties to choose from here is a sample of a few to consider:

  • 'Jackmanii' - An all-time classic that is dependable and easy to take care of. Produces purple flowers in June, July with light repeat bloom through the later part of the season. Pruning group C
  • 'Comtesse de Bouchard' - Very vigorous clematis and one of the more popular pink varieties. Blooms in July-August. Pruning group C
  • 'Cardinal Wyszynski' - Large crimson flowers. Free flowering blooming in July, Aug, September. Pruning group B
  • 'Vyvyan Pennell' - Outstanding double flowering clematis. Double flowers are produced on last season's growth, single flowers produced on current season's growth. Pruning group B
  • Sweet Autumn Clematis - A dependable, vigorous late-blooming clematis. Fragrant. Benefits from very severe pruning. Pruning group C
  • Clematis tangutica - Small-flowered species type. Robust, heat, and drought tolerant. Blooms July-October. Produces very attractive seed heads. Pruning group C
  • 'Roguchi' - Clematis with a very long flowering season blooming from June - September

Additional notes:

  • Clematis is perhaps the most popular and most often planted perennial vine.
  • Clematis, Image Credit: Oliver Ash on Unsplash.com