Climber
Clematis
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Flowers | Flowers in March | Flowers in April | Flowers in May | Flowers in June | Flowers in July | Flowers in August | Flowers in September | |||||
| Plant | Plant in March | Plant in April | Plant in May | Plant in September | Plant in October | |||||||
| Prune | Prune in February | Prune in March | Prune in June | |||||||||
| Looks good | Looks good in April | Looks good in May | Looks good in June | Looks good in July | Looks good in August | Looks good in September |
Overview
Clematis is a huge genus of mostly twining climbers that pull themselves up by wrapping leaf stalks round supports. With careful choice you can have flowers almost all year. Clematis cirrhosa blooms in winter, C. alpina and C. montana in spring, large-flowered hybrids such as 'Nelly Moser' and 'The President' in early summer, and C. viticella types like 'Etoile Violette' from midsummer, followed by the yellow lanterns and silky seedheads of C. tangutica 'Bill MacKenzie'.
Where to grow clematis
Clematis like their heads in the sun and their roots cool. Train them on trellis, an obelisk, a fence or through a shrub or tree, and shade the base with low plants or a paving slab. They grow well on chalky and clay soils. Vigorous montanas need a large wall or tree.
Planting
Plant in spring or early autumn. Dig a generous hole, add compost, and set the root ball so the top is 5–8 cm below the soil surface. Water heavily and guide the stems to the support with the cane they came on.
Care through the year
Spring
Tie in new shoots weekly, as they tangle quickly, and protect young growth from slugs.
Summer
Water deeply in dry spells and feed with a high-potash fertiliser to keep flowers coming.
Autumn
Plant new clematis while the soil is still warm.
Winter
Leave the seedheads of later kinds for frost and birds to enjoy.
Pruning
Group 1 (winter and spring bloomers such as montana and alpina) needs only a tidy after flowering. Group 2 (large early hybrids) gets a light trim in February to the first pair of fat buds. Group 3 (summer and autumn bloomers) is cut back hard each February to about 30 cm above the ground.
Propagation
Layer a long stem into a buried pot in spring or summer. Internodal cuttings, cut midway between leaf joints, root in early summer.
Common problems
Clematis wilt can collapse large-flowered hybrids overnight; cut affected stems to healthy wood or ground level, and deep-planted plants usually regrow. Slugs, aphids, earwigs and powdery mildew are the other common nuisances.
Something else wrong? Diagnose it by symptom.
Month-by-month reminders
Jobs for this plant come round in February, March, April, May, June, September and October. Each month page lists everything else worth doing in the garden at the same time.
Related plants
Sources
Botanical names follow Kew's Plants of the World Online; growing attributes were checked against the references below. Text is our own. See our editorial policy.