A Guide to Climbing Clematis Plants
The flexible, flowering stems of clematis provide many ways to create exciting effects in the garden, and with a vast range of colors, shapes and forms to choose from, it’s no wonder they’re so popular. From tree huggers to container varieties, there’s a clematis for every garden size and flowers for almost every month of the year.
Clematis comprise a large group of climbers and include a range of different flower types and growth habits. The larger species, such as Clematis montana and C. tangutica, need little support when allowed to scramble through host trees and shrubs. The large- and late-flowering hybrids are not as vigorous and, like all clematis, need wires or trellis to climb vertical structures. Late-flowering viticella types are similar in habit to the large species and ideal for weaving through host plants.
Clematis offer a rich source of exciting features for year-round displays, with patio hybrids, large-flowered early summer performers, the subtle, bell-like blooms of late-flowering species, and the sweet aroma of winter- and early spring-flowering forms. And for the brief moment in midwinter when clematis are not in bloom, C. tangutica brightens gloomy days with its lantern-shaped seedheads.
Some clematis types, such as C. montana and its cultivars, can reach up to 30 feet, and when planted with a host tree that flowers just before its late spring blooms appear, the pair provide many weeks of color. The late-flowering viticella types also make good partners for trees and shrubs, or allow them to scramble through herbaceous plants in a border.
To cover a wall, fence or screen, train a large clematis along wires. A good choice for late-season color is C. ‘Bill McKenzie’, which forms a tangle of leafy stems and bright yellow nodding flowers followed by decorative seedheads. The myriad clematis hybrids afford eye-catching displays for pergolas, arches and posts, and all combine well with climbing roses, jasmine and annual morning glory (Ipomoea).
Plant clematis in moist but well-drained, fertile soil; they thrive in full sun or partial shade. Keep the roots cool by shading them with other plants or placing a layer of pebbles or flat stones at the base. To prevent the fungal disease clematis wilt, plant in deep, fertile soil, and ensure the plant’s roots don’t dry out.
Pruning Clematis Plants
There are three methods of pruning clematis: most plant labels will tell you which group your plant belongs to, and when it is best to prune.
- Group 1: Clematis that flower in winter or spring, such as C. montana need no pruning, but you can thin them out a little just after flowering if stems are congested, cutting back to healthy buds.
- Group 2: Early summer-flowering clematis, including the large-flowered hybrids, require light pruning. Remove dead and diseased growth, and cut back remaining stems to a pair of healthy buds.
- Group 3: Clematis that flower after midsummer should be cut back hard in winter or early spring. Prune the stems to a pair of strong buds 6–12 inches above the ground. New stems will soon appear.