Clematis

Clematis spp. · Flower

Quick answer: Water: About 1 in per week in dry spells (estimated). Light: Full sun to part shade, at least 4–5 hours. Soil: Moist, well-drained, rich in organic matter; pH 6.0–8.0. Pets: Toxic to cats and dogs according to the ASPCA; chewing it can irritate the mouth and upset the stomach. Wear gloves when handling it, and ask your vet if in doubt.

A climbing vine with large, showy flowers that likes its head in the sun and its feet in the shade. Varieties differ mainly in when they bloom, and that decides how you prune. Given a support and cool roots, it keeps flowering for many years.

💧WaterAbout 1 in per week in dry spells (estimated)

☀️LightSun on top, shaded roots

🐾PetsToxic to cats & dogs

Care at a glance

Light: Full sun to part shade, at least 4–5 hours
Water: About 1 in per week in dry spells (estimated)
Soil: Moist, well-drained, rich in organic matter; pH 6.0–8.0
Temperature: Hardy in USDA zones 3–9
Spacing: Planting hole 18 in wide and deep; 2–3 ft between plants (estimated)
Container: At least 18 in deep and wide (estimated)
Bloom/Growth: Early spring, late spring or summer–fall, by pruning group
Lifespan: Perennial vine; 1–18 ft tall depending on type

When?

Plant in spring once the ground can be worked, or in early fall while the soil is still warm (estimated). Put the support in place before planting so you do not damage the roots later.

Step by step

Dig a hole about 18 × 18 × 18 in and mix in plenty of compost.
Set the plant deeper than it sat in the pot, so the first two sets of leaf nodes are buried.
Give it a trellis, fence or obelisk to climb right away.
Mulch 2–4 in deep over the root zone, keeping it 4–6 in away from the stem.
In the first spring after planting, cut the stems back to about 12 in to encourage more shoots.
Group A (blooms on old wood): prune lightly just after spring flowering.
Group B (blooms twice): trim lightly after the first flush; Group C (summer bloom): cut back hard to 8–12 in in early spring.
Feed during the growing season with a slow-release, low-nitrogen fertilizer; follow the label.

Common problems

Few or no flowersUsually pruned at the wrong time for its group; check the variety label.

A whole stem suddenly wiltsCan be a fungal wilt; cut back to healthy growth, new shoots usually come from below.

Weak growth, roots drying outRoots are too hot; add mulch or low plants to shade the base.

Stems tangled and sprawlingNot enough support; tie young shoots to the frame.

Pets

Toxic to cats and dogs according to the ASPCA; chewing it can irritate the mouth and upset the stomach. Wear gloves when handling it, and ask your vet if in doubt.

Similar plants

Wisteria Pink Jasmine Rose

Sources

This page is general guidance; no pesticide doses are given.