Clematis Pruning Advice
Clematis plants may be divided into three major categories, based on when and how they flower. These are commonly referred to as:
- Group 1
Those that flower in spring or early summer on last year's wood. - Group 2
Those that flower in summer on last year's wood. Occasionally, they may also flower a second time in late summer on the current year's growth. - Group 3
Those that flower from mid to late summer (sometimes even into autumn) on the current year's growth.
The choice of pruning method for all clematis plants depends on which group they fall into:
It is therefore important to find out and note which group that your clematis falls into; if you have inherited an unknown plant, simply knowing how and when it flowers should give you the information needed to determine its group.
It is vital to train and tie-in new shoots as they develop, especially during the spring when growth is most vigorous. This applies to all three groups of clematis.
Group One
Features
Vigorous climber, flowers in spring or early summer on last season's ripened stems. Typically has small blooms.
Examples
- Clematis alpina (and cvs)
- Clematis armandii (and cvs)
- Clematis cirrhosa
- Clematis macropetala (and cvs)
- Clematis montana (and cvs)
Pruning Method
Other than when it is first planted, this vigorous type of clematis usually requires very little pruning. If it becomes tangled, it may be pruned after flowering, removing any obvious dead growth completely. This will produce new growth during the summer and autumn that will provide flowers the following spring. Any excess growth should be removed in autumn.
Group Two
Features
Fully frost-hardy cultivars that produce large flowers in early to mid-summer on stems that arise from last season's ripe wood. This group may also produce a smaller crop of flowers on the current season's growth in the late summer or early autumn.
Examples
- Clematis 'Barbara Jackman'
- Clematis 'Belle of Woking'
- Clematis 'Lasurstern'
- Clematis 'Marie Boisselot'
- Clematis 'Nelly Moser'
- Clematis 'The President'
- Clematis 'Vyvyan Pennell'
Pruning Method
This group requires only a light pruning in early spring, before the plant starts active growth. Cut the old growth back to the highest pair of strong buds; growth from these buds will produce the current season's flowers. After the first flush of flowers, cut out about a quarter of the flowered shoots to ensure a good early flowering the following year.
Group Three
Features
Includes large and small-flowered cultivars that flower from mid- to late summer, and sometimes through to autumn on the current year's stems.
Examples
- Clematis 'Ernest Markham'
- Clematis florida (and cvs)
- Clematis 'Gipsy Queen'
- Clematis 'Hagley Hybrid'
- Clematis 'Jackmanii'
- Clematis 'Perle d'Azur'
- Clematis tangutica (and cvs)
- Clematis 'Ville de Lyon'
- Clematis viticella (and cvs)
Pruning Method
This group requires hard pruning in the early spring - before the plant starts active growth. Cut the shoots back to a pair of buds about 15-30 cm (6-12 in) from the ground to encourage strong new shoots from close to the base. Tie in new shoots as they develop during the spring and summer; however, do bear in mind that these tend to be quite brittle, so take great care in handling them.