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Vines & Groundcovers
Clematis spp.
clematis
Ranunculaceae
Worldwide temperate regions; species in cultivation from Europe, Asia, North America, and Australasia
At a Glance
TypeVine
HabitClimbing
FoliageDeciduous
Height3-30 feet (0.9-9 m)
Width3-10 feet (0.9-3 m)
Maturity4 years
Growing Zones
USDA Hardiness Zones
3 - 9Zone 3
Zone 4
Zone 5
Zone 6
Zone 7
Zone 8
Zone 9
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy
Key Features
Attracts Pollinators
Attracts Butterflies
Container Friendly
Native to North America
Maintenancemoderate
Overview
Clematis is a genus of approximately 300 species of deciduous and semi-evergreen climbing vines in the buttercup family (Ranunculaceae), with thousands of cultivars extending the ornamental range to nearly every color, flower size, and season. In Pacific Northwest gardens, clematis climbs by twisting its leaf stalks (petioles) around supports — not tendrils or aerial rootlets — and requires a trellis, fence, wire, or other structure with elements narrow enough to grip, typically 0.25–0.5 inch (6–12 mm) in diameter. Flower form ranges from the enormous dinner-plate blooms of large-flowered hybrids (up to 8–10 inches / 20–25 cm across) to nodding lanterns, small stars, and tubular bells in smaller species types. Bloom seasons span from late winter (*C. cirrhosa*) through spring (*C. montana*, *C. alpina*), early summer (large-flowered hybrids), and late summer to fall (*C. viticella*, *C. tangutica*, *C. terniflora*). Height ranges from 3–4 feet (90–120 cm) for compact cultivars to 20–30 feet (6–9 m) for vigorous species. The roots prefer cool, moist, shaded conditions — the traditional guidance 'head in the sun, feet in the shade' reflects this accurately. The Pacific Northwest's cool moist climate is excellent for clematis overall, supporting vigorous growth, rich flower color, and reduced susceptibility to clematis wilt (*Phoma clematidina*) compared to hotter, drier climates. Understanding pruning group (1, 2, or 3) is essential before purchasing or maintaining any clematis — pruning at the wrong time destroys the following season's bloom.
Native Range
The genus Clematis is distributed across temperate regions worldwide. Species commonly grown in PNW gardens include: Clematis alpina and C. macropetala (Europe, Asia), C. montana (Himalayas, China), C. viticella (southern Europe), C. tangutica (Central Asia, China), C. terniflora (Japan, China, Korea), C. integrifolia (Europe), and hundreds of large-flowered hybrids of complex parentage.Suggested Uses
Clematis is one of the most versatile climbing plants for PNW gardens. Group 1 and 2 types are excellent on trellises, pergolas, fences, and scrambling through shrubs or small trees. Group 3 types work well over summer structures, through roses, and on obelisks in borders. Compact cultivars grow in large containers. Native and pollinator gardens benefit from the nectar value and ornamental seed heads of species types. Pairing early Group 1 species with late Group 3 cultivars extends the vertical flowering season from April through October. The feathery seed heads of many species provide winter interest.How to Identify
Appearance
Size & Dimensions
Height3' - 30'
Width/Spread3' - 10'
Reaches mature size in approximately 4 years
Colors
Flower Colors
white
pink
red
purple
lavender
blue
yellow
Foliage Colors
green
Fall Foliage Colors
no change
Bloom Information
Bloom Period
~8 weeksJ
F
M
A
M
J
J
A
S
O
N
D
SpringSummerFall
Detailed Descriptions
Flower Description
white, pink, red, purple, lavender, blue, yellow, or bicolor depending on species or cultivarFoliage Description
medium to dark greenGrowing Conditions
Sun Requirements
Full Sun
Partial Shade
Requires 4-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Soil Requirements
pH Range6.5 - 7.5(Neutral)
357912
Soil Types
loamchalkclay
Drainage
well drained
Water & Climate
Water Needs
Medium
Frost Tolerance
hardy
Time to Maturity
3-5 years
Care & Maintenance
Care Guide
The most critical care decision for clematis is identifying the correct pruning group before pruning — incorrect pruning removes all flowers for a full season. Keep roots cool and moist: plant with 2–4 inches (5–10 cm) of mulch over the root zone or position a low groundcover or paving stone to shade the roots while the top growth reaches sunlight. Clematis prefers well-drained, slightly alkaline to neutral soil (pH 6.5–7.5); amend acidic PNW soils with lime if needed. Water consistently, especially through the first two seasons. Clematis wilt (sudden stem blackening) is most damaging on large-flowered hybrids but rarely kills the plant — cut affected stems to ground level and the plant typically resprouts from below-ground buds. Deep planting (burying the crown 2–3 inches / 5–8 cm below soil level) at installation provides insurance against wilt.Pruning
Pruning group determines everything. Group 1 (early spring bloomers on old wood — C. montana, C. alpina, C. cirrhosa, C. armandii): do NOT prune hard; remove dead or damaged stems and lightly tidy immediately after flowering. Hard pruning removes all flower buds. Group 2 (large-flowered hybrids blooming May–June on old wood with a second flush on new wood): remove dead and weak stems in late winter (February through March) and lightly tidy after the first flush; do not cut hard below the lowest pair of healthy buds. Group 3 (late bloomers on new growth — C. viticella, C. tangutica, C. terniflora, most late-season hybrids): cut all stems back hard to 12–18 inches (30–45 cm) from the ground in late winter (February through March). If the pruning group is unknown, observe when and from where the plant blooms for one full season before pruning.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
early spring
Maintenance Level
moderateContainer Growing
✓ Suitable for container growing
Minimum container size: 10 gallons