Clematis is a genus of climbing vines popular in gardens for their very showy flowers and attractive, whirlwind-like seed clusters shortly after. Since the flowers are the most important aspect of these plants, their bloom time dictates when and how to prune clematis.
Once you know a little about your own plant, this step-by-step guide will help you through the pruning process of your specific variety.
When to Prune Clematis
Flowers are the most important impact of clematis, so keeping them blooming strong every year is the main goal for pruning clematis. Know when your clematis blooms.
- Early-spring blooming: Prune right after flowering has finished.
- Mid-spring or later blooming: Prune in early spring before buds swell and growth begins. How you cut, however, will depend on whether the plant blooms in spring or late summer.
If you just planted your clematis, you might consider sacrificing green growth and flowers in exchange for root growth that makes a strong plant in the long term. Ruth Gooch, the author of "Clematis The Complete Guide," suggests hard pruning all one- to three-year-old clematis down to the second set of strong buds above ground level.
This method will sacrifice most of the flowers if the plant is a spring-bloomer. This is worth it if you can wait for flowers, but maybe you can compromise with your plant: You might try cutting down nearly all of your vine as Ruth suggests, but leaving a few trained canes up until they flower.
Equipment / Tools
- Stepladder (if needed)
- Arbor or trellis
In pruning clematis, your overall goal is to create a plant that will flower strongly each year at various heights from ground level to a comfortable height where you can enjoy and reach the plant for maintenance. By pruning, you control the size, keep the plant trained to its armature, and create the space for new growth to replace old wood.
Choose Your Size
Start by deciding what size you want your plant to eventually be at maturity. This is probably determined by the size of your armature, but keep in mind that you want to be able to reach the top to prune and train it. Are you willing to climb a ladder?
Prune for Your Variety
Continue your pruning by noting your variety of clematis, when it will bloom, and if it will develop wood. At the right time of year, cut back late bloomers to the ground and matured spring bloomers to their original framework of tidy, strong, trained stems.
If it’s a woody clematis, select old canes to cut back all the way to the ground, stimulating strong new growth, a textured look, and exposing all levels of the plant to light and new growth.
Deadheading sends energy to create more flowers but prevents the whirlwind-like seedheads from forming.
Train the Vines
Clematis are fast growers that cannot support themselves. If you don’t want them scrambling across the ground and nearby shrubs, you must provide an armature such as a trellis or arbor. Make sure your armature is strongly built, perhaps anchored to a wall. Expect to have to tie your clematis to it, or at least periodically wrap the plant to the structure by hand. Don’t expect a wall alone to provide support: unlike ivy, clematis cannot cling to a bare vertical surface.
If you want a more informal look, you certainly can try letting your vines scramble on the ground or perhaps on a nearby standing dead shrub. You may work harder to control the display, and you may need a lot more space than if you just dedicated a trellis to the cause. But it’s your garden—your rules.
Common Mistakes in Pruning Clematis
Too afraid to prune: If you never prune your clematis because you are afraid you’ll do wrong...well, don’t be. If you ignore any vine it will fast become a weed, and clematis is too special to be weeds. Neglected clematis grow tall and bear flowers too high to see, or scramble all around, shade themselves, and bear flowers sparsely. You can do better.
Pruning hard at the wrong time: If you prune a little, it’s okay to prune at the wrong time. If you prune at the right time, it’s okay to prune a lot (“hard”). But if you prune hard at the wrong time, especially if you are shearing off the whole outside of the plant (a bad technique), you won’t see any blooms that year.