How-to Guide
How to Grow Clematis
The short answer
Clematis succeeds on three habits. First, plant deep: the RHS advises setting the crown about 10cm (4in) below the surface, which encourages spare buds below ground that can regrow if stems are damaged, and position the plant at least 30cm away from a wall or fence base where soil is dry. Second, give the leaf-stalk tendrils something thin to grip, like mesh, wire, or netting on the support.
Third, prune by group, which is set by bloom time. Group 1 (winter/spring bloomers on old wood): prune only after flowering, if at all. Group 2 (large-flowered, May-June): light pruning in late winter plus a tidy after the first flush. Group 3 (late summer bloomers on new wood): cut hard to about 30cm in late winter. Lost the label? Watch when it flowers for a year.
What clematis is
Clematis is a large genus of mostly climbing vines, from vigorous spring-flowering montanas to compact large-flowered hybrids and late viticellas. They climb by wrapping leaf stalks around thin supports, which is why they cannot climb a bare wall or thick post without added mesh or wires.
With species for nearly every aspect and bloom season, most gardeners can keep a clematis in flower from spring to fall by combining groups.
Planting clematis
- 1Site it — Most clematis flower best with their tops in sun; plant at least 30cm (1ft) out from walls or fences, where rain actually reaches the roots.
- 2Plant deep — Set the root ball so the crown sits about 10cm (4in) deeper than it grew in the pot. Buried stem buds insure the plant against damage and disease.
- 3Provide a climbable support — Fix trellis, netting, or horizontal wires slightly off the wall so the leaf tendrils can wrap; tie young stems in until they take hold.
- 4First-spring formative prune — Unless the plant already has 3-4 strong basal stems, cut all newly planted clematis back to a strong pair of buds about 30cm above soil the first spring to force multiple stems.
✔ Keep the root zone cool and moist with mulch or a groundcover, and water new plants generously through their first summer.
The three pruning groups
- Group 1 — flowers roughly January to May on the previous year's wood (montana, alpina, macropetala, evergreen types). No routine pruning; tidy or reduce size immediately after flowering only.
- Group 2 — large-flowered hybrids blooming May-June on old wood, often repeating later. In late winter/early spring remove dead and weak stems and cut remaining stems back to a strong pair of buds; lightly deadhead/tidy after the first flush to encourage the second.
- Group 3 — late-summer bloomers on the current year's growth (viticella, texensis, many herbaceous types). Cut every stem back to a pair of strong buds about 30cm above ground in late winter. Skip this and flowers migrate to the top of a bare, tangled base.
Common problems
Sudden wilting of one or more stems on large-flowered hybrids is the notorious clematis wilt; deep planting is the classic insurance, since plants can regrow from buried buds after affected stems are cut out. Otherwise expect the ordinary vine issues: drought stress in the rain shadow of walls, aphids on soft tips, and mildew on crowded growth.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- Royal Horticultural Society — How to Grow Clematis (Growing Guide) — Plant clematis about 10cm deeper than pot level and at least 30cm from a wall/fence; first-spring hard prune of new plants to ~30cm above strong buds; general culture
- Royal Horticultural Society — Pruning Clematis (Beginner's Guide) — The three clematis pruning groups defined by flowering time and age of flowering wood, with timing for each
- Royal Horticultural Society — Clematis Pruning Group Three — Group 3 clematis flower on current-season growth and are cut back hard in late winter