Pruning Clematis
Thoughtful pruning produces far more flowers
The cheerful blooms of the clematis vines are among the highlights of any garden. And if you let your clematis scramble at will, untamed, they will certainly flower. But your display will be far more impressive if you prune them carefully and at the right time. Different types require different treatment, so it’s important to know, first off, which varieties are which, and secondly, how to prune the ones you have.
Local Advice for Local Gardners
Pruning Groups
To help you prune your clematis the right way, clematis varieties are divided into three pruning groups according to when they flower and how the flowers are produced. Varieties in each group require different pruning treatment; it’s not complicated, but it’s important to get it right.
Group One Clematis
- Spring-bloomers, with flowers in clusters - Flowers are carried on individual stalks, from stems which grew the previous year. These are the first clematis to bloom in the Spring.
- Varieties include all C. alpina, C. macropetala, and C. montana varieties as well as a few which can be grown in a large conservatory including C. cirrhosa and C. x cartmanii.
- Prune new plants in early Spring by cutting them back to about 1 ft as growth starts to encourage the plant to produce new growth from the base. This may seem drastic, but it will produce the best flowering results.
- Prune established plants by cutting back all shoots to about 3 ft early in their second Spring to further promote growth from low down. Every year after that simply cut out weak or dead shoots after flowering. If space is limited, cut out all shoots that have flowered immediately after flowering.
- Old, overgrown plants can sometimes be rejuvenated by cutting back ferociously to about 2 ft in Spring - but sometimes this can kill the plant. If the plant is thriving, but bare at the base, pin down a stem into the ground in front of the old plant and it will usually grow. Prune the resulting new plant as above.
Group Two Clematis
- Spring-bloomers, with repeat flowers later, with individual blooms - The first flowers are produced individually in Spring, sometimes on long stems, on growth made the previous year. Later in the season thr flowering period is extended as flowers bloom on the new growth produced earlier the same year. This group in general gets the lightest pruning.
- Varieties include most double-flowered varieties, and early and mid-season large flowered types. Examples include 'Blue Light', 'Claire de Lune", "Crystal Fountain', 'Frankiska Maria', 'Henryi', 'Josephine', 'Niobe', 'Silver Moon', 'Veronica's Choice' and 'Will Goodwin'. Prune new plants in Spring by cutting them back to about 1 ft as growth starts. This will encourage more growth from the base and help prevent "bare legs". This may seem drastic, but it will produce results.
- Prune established plants in early Spring by cutting back all shoots to about 3ft in their second year to encourage a bushy framework then, annually in early Spring, trim shoots back lightly to just above a fat pair of buds. Cut out any weak or dead growth.
- Old, overgrown plants can be restored in a two year process. Cut half the plant back to about 2 ft as the buds start to burst inm Spring and then prune as above. Repeat the process on the other half the following year.
Group Three Clematis
- Summer and Fall Bloomers - Flowers are carried in clusters on growth produced earlier the same year.
- Varieties include 'Arabella', 'Betty Corning', 'Bonanza', C. florida varieties, 'Jackmanii', 'My Angel', C. texensis varieties, 'Ville de Lyon' and C. viticella varieties and all other late flowering clematis.
- Prune new plants in Spring by cutting them back to about 1 ft as growth starts
- Prune established plants in Spring by cutting them back as growth begins to 1 to 1 1/2 ft above ground. Hard winters may kill the stems to a lower level, in which case cut back to where buds are swelling and cut out all dead growth.
- Overgrown plants can sometimes be rejuvenated by cutting back to 2 ft in Spring, but this may also kill the plant. If the plant is thriving, but bare at the base, peg down a stem in front of the old plant and, when it has rooted and produced new growth, prune the resulting new plant as above.
Written by Graham Rice