How to grow Clematis

Clematis · leather flower

Climbing perennial grown for its showy flowers; bought as a plant and trained on a trellis, wall or fence. Choosing different groups gives flowers from late winter to autumn. All parts are toxic to cats, dogs and horses, and the sap can irritate skin.

Quick facts

Type	Flower
Family	Ranunculaceae
Light	Full sun
Soil pH	6.5–7.5
Frost	tolerates light frost
Soil for sowing	from 5 °C
Where it grows	Open ground

When to plant

Planted as a young plant from a nursery while it is dormant — in early spring before the buds open, or in autumn after leaf fall.

Frost dates · When to plant

Care

Open ground

Stage	Watering	Temperature	Feeding
Growth	every 7 days	—	phosphorus and potassium, at the start of the stage; phosphorus and potassium, 35 days into the stage
Flowering	every 7 days	—	—

Growing notes

Light

Best with at least six hours of sun on the leaves while the roots stay cool and shaded; give afternoon shade in hot climates. Flowering is poor in deep shade.

Soil

Deep, fertile, moist but well-drained soil, neutral to slightly alkaline (pH 6.5–7.5). Waterlogged ground is unsuitable.

Care

Plant in spring or early to mid autumn. Set large-flowered hybrids with the top of the root ball 5–7.5 cm below the soil, spring-flowering types just below the surface. Shade the roots with mulch or low plants. Water deeply once a week in dry weather, about 25 mm, soaking the soil 30 cm down. In fertile ground a spring mulch of compost is enough; on poor soil or in a container give a low-nitrogen fertiliser every 4–6 weeks in spring and early summer, but not while it is flowering. Prune by group — 1, spring-flowering, right after flowering; 2, large-flowered early summer, lightly in late winter; 3, flowering from midsummer, hard in late winter. Watch for clematis wilt, slugs on young shoots, aphids and, in pots, vine weevil.

Pests and diseases of Clematis

Vine weevil

Sources

Figures checked against these sources.