Clematis

SpringSummer

4a–9bHardiness zone

Peak bloom windowZone 6b · frost-offset weeks

Winter

Not in bloom

Spring

Peak bloom

Summer

Peak bloom

Fall

Not in bloom

Peak bloom

In bloom

Peak bloom windowZone 6b · frost-offset weeks

Winter

Not in bloom

Spring

Peak bloom

Summer

Peak bloom

Fall

Not in bloom

Peak bloom

In bloom

Background

Clematis is the classic companion to roses — the two climb together naturally, clematis threading through rose canes to add colour before, during, and after the main rose flush. There are three pruning groups: Group 1 (spring-flowering, prune after bloom), Group 2 (large-flowered hybrids, light prune in early spring), and Group 3 (late-flowering viticella types, cut hard to 12 inches in late winter). For mixed plantings with roses, Group 2 and 3 varieties are most useful.

The cardinal rule is 'cool roots, warm top': mulch deeply at the base and plant with the crown 2–3 inches below soil level to protect the growing point. Clematis wilt can strike suddenly, collapsing a stem overnight — cut back to healthy tissue and the plant almost always recovers from the protected crown.

Not sure when to prune this one? Read the Clematis Growing Guide — the three pruning groups and when to cut each.

Good companions

Rose

Care guide

SunFull sun to partial shade — 'feet in the shade, head in the sun'

WaterModerate; deep watering weekly; mulch heavily to keep roots cool

SoilRich, well-draining, slightly alkaline; add lime if soil is acidic

Spacing18–24 inches

Height6–20 feet (climber)

Zone4a – 9b

Frost hardy

Seasonal tasks

spring

cutGroup 3: cut all stems back hard to 12 inches before new growth starts — all of this season's flowers come on the new wood that follows

cutGroup 2: light tidy only — work down each stem to the first strong pair of fat buds and cut just above; keep most of the framework or you lose the early flush

watchWatch for clematis wilt — cut affected stem to base immediately; plant usually recovers from the deep-planted crown

watchTie in new growth every 2 weeks — stems are brittle and snap in wind if left untrained

summer

watchWatch for clematis wilt — cut affected stem to base immediately; plant usually recovers from the deep-planted crown

watchTie in new growth every 2 weeks — stems are brittle and snap in wind if left untrained

Common problems

Powdery mildew

Symptoms

White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.

Treatment

Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.