Pruning Guide for Clematis
Pruning clematis (Clematis spp.) involves specific techniques to ensure this popular climbing plant's health, vigor, and flowering. Known for their stunning flowers, clematis vines can be categorized into three main pruning groups based on their flowering time and growth pattern. Understanding these groups is crucial for pruning success.
Pruning Groups
Group 1: Early-Flowering Clematis
Botanical Names: Clematis that bloom on the previous year's growth. Examples include Clematis montana and Clematis alpina.
Pruning Time: Prune after flowering, usually late spring to early summer.
Pruning Approach: Light pruning. Remove dead or weak stems, and lightly shape the plant. Major pruning isn't recommended as it may reduce flowering the following year.
Group 2: Large-Flowered Hybrids
Botanical Names: Includes hybrids that bloom both on last year's growth and the current year's growth. Examples are Clematis 'Nelly Moser' and Clematis 'Henryi.'
Pruning Time: Late winter or early spring.
Pruning Approach: Moderate pruning. Cut back the previous year's stems to a pair of strong buds about 6-8 inches above the ground, ensuring some old wood remains to produce early blooms.
Group 3: Late-Flowering Clematis
Botanical Names: Clematis that bloom on current year's growth, such as Clematis viticella and Clematis 'Jackmanii.'
Pruning Time: Late winter or early spring.
Pruning Approach: Hard pruning. Cut back all stems to a pair of strong buds about 12-18 inches above ground level to encourage vigorous growth and abundant blooms.
General Pruning Tips
Tool Preparation: Use sharp, clean pruning tools to make clean cuts and avoid disease transmission.
Health Inspection: Before pruning, inspect the vine for signs of pests, diseases, or damaged stems. Remove any unhealthy parts first.
Training and Support: Regularly train new growth by gently tying stems to their support structure to encourage vertical growth and spread.
Mulching and Feeding: After pruning, apply a layer of mulch and consider a balanced fertilizer to support new growth.
Group 1 - Early Bloomers
Bloom Time: Early in the year on shoots produced the previous season.
Pruning Time: Immediately after flowering in mid- to late spring.
Special Notes: Minimal pruning, just to shape or manage size; avoid very old wood.
Varieties:
Clematis 'Helsingborg'
Clematis alpina
C. alpina 'Pamela Jackman'
C. armandii
C. × cartmanii 'Avalanche'
C. × cartmanii 'White Abundance'
C. cirrhosa
C. cirrhosa var. balearica
C. cirrhosa 'Freckles'
C. cirrhosa 'Wisley Cream'
C. 'White Columbine'
C. 'Constance'
C. 'Frances Rivis'
C. macropetala
C. macropetala 'Blue Bird'
C. 'Markham's Pink'
C. montana
C. 'Rosy O'Grady'
C. 'Ruby'
Group 2 - Large-flowered Hybrids
Bloom Time: May to June, and possibly again late summer on new growth.
Pruning Time: Late winter or early spring and after the first flush of flowers in early summer.
Special Notes: Moderate pruning to encourage both early and late blooms.
Varieties:
'Barbara Jackman'
'Bees' Jubilee'
'Belle of Woking'
'Beauty of Worcester'
'Burma Star'
'Doctor Ruppel'
'Duchess of Edinburgh'
'Edith'
Clematis florida var. sieboldiana
'Jackmanii Alba'
'Jackmanii Rubra'
'Marie Boisselot'
'Matka Teresa'
'Nelly Moser'
'Snow Queen'
'The President'
'Rebecca'
'Royal Velvet'
'William Kennett'
Group 3 - Late Bloomers
Bloom Time: Late summer on growth made in that season.
Pruning Time: Late winter or early spring.
Special Notes: Hard pruning back to strong buds within 1ft of the ground; suitable for herbaceous types.
Varieties:
'Abundance'
'Alionushka'
'Étiole Violette'
'Ernest Markham'
'Duchess of Albany'
'Gravetye Beauty'
'Lady Betty Balfour'
'Polish Spirit'
'Princess Diana'
'Royal Velours'
'Ville de Lyon'
'Sir Trevor Lawrence'
C. × triternata 'Rubromarginata'
C. viticella
C. viticella 'Purpurea Plena Elegans'
C. heracleifolia
C. integrifolia
C. recta
FAQ
Can I prune a clematis in summer?
Pruning in summer is typically reserved for deadheading Group 2 clematis to encourage a second bloom and for light maintenance, such as removing dead or weak stems.
What happens if I don't prune my clematis?
Failure to prune can result in a tangled mass of stems, reduced flowering, especially at eye level, and potentially unhealthy plants due to poor air circulation.
How do I revive an old clematis?
Even neglected clematis can often be revived. Begin by identifying its pruning group. If uncertain, observe its blooming pattern for a year. Next, gradually prune over two to three seasons to rejuvenate the vine without overly stressing it.
Pruning clematis encourages strong growth, improves flowering, and maintains the plant's shape and health. Whether you're caring for early, midseason, or late-flowering varieties, understanding their specific pruning needs ensures these stunning climbers remain a highlight in the garden for years to come.