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Clematis 'Duchess of Edinburgh'

Duchess of Edinburgh Clematis

Ranunculaceae

Garden hybrid; bred in England (1875)

Attracts Pollinators Deer Resistant Container Friendly

SunFull Sun – Part Shade

WaterMedium

HardinessZones 4–9

Overview

Clematis 'Duchess of Edinburgh' is a deciduous climbing vine reaching 8-10 feet (2.4-3 m) tall with a 3-6 foot (90-180 cm) spread when supported. Stems become woody at the base; new growth twines via leaf petioles around supports up to 0.4 inch (1 cm) in diameter. Compound leaves bear three leaflets, each 2-3 inches (5-8 cm) long, ovate with pointed tips, mid-green and turning yellow before falling in autumn. First-flush flowers are fully double, 4-5 inches (10-13 cm) across, pure white with pale green tints in the central petaloids; each bloom carries 60-80 petal-like sepals arranged in a rosette. Main flowering occurs late May through June on previous season's wood, with a smaller second flush in August-September on new growth that produces semi-double or single blooms. Individual flowers last 7-10 days. Plants take 3-4 years to reach mature size after planting and grow more slowly than many large-flowered Clematis spp. hybrids. Susceptible to clematis wilt (Calophoma clematidina) in years 1-3; affected stems collapse rapidly but plants typically regenerate from the crown when set 2-3 inches (5-8 cm) below soil level. Lower stems become bare with age.

Native Range

A garden hybrid of Clematis spp. not found in the wild. Bred by the George Jackman & Son nursery in Woking, England, and introduced in 1875. Parentage involves crosses between C. lanuginosa and C. florida types common in mid-Victorian Clematis spp. breeding.

Suggested Uses

Grown on trellises, obelisks, and pergolas at 6-8 feet (1.8-2.4 m) of support height, and through climbing roses or shrubs that shade the root zone. Container culture works in pots of at least 18 inches (45 cm) diameter and 18 inches (45 cm) deep with well-draining mix; lower-growing perennials are commonly planted at the base to cover the bare lower stems.

How to Identify

Distinguished by fully double pure-white flowers 4-5 inches (10-13 cm) across with 60-80 petal-like sepals in tight rosette form. Central petaloids show pale green tints on early-season flowers, fading to white in summer blooms. Compound leaves carry three pointed-ovate leaflets, each 2-3 inches (5-8 cm) long. Second-flush flowers in August-September are typically semi-double or single rather than fully double.

Appearance

Size & Dimensions

Height8' - 10'

Width/Spread3' - 6'

Reaches mature size in approximately 4 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~5 weeks

Spring Summer Fall

Main flush late May through June in zones 6-8, carried on previous season's wood. A second flush appears August through September on new growth. Individual blooms last 7-10 days; first-flush bloom duration is 4-5 weeks. Cool spring temperatures extend first-flush bloom by 1-2 weeks; temperatures above 85°F (29°C) shorten individual flower lifespan.

Detailed Descriptions

Flower Description

white with pale green tints in early flowers

Foliage Description

mid-green; yellow in autumn

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-6 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 Range6.0 - 7.5(Neutral)

357912

Soil Types

loam clay

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

3-4 years to mature size

Care & Maintenance

Care Guide

The crown is typically set 2-3 inches (5-8 cm) below soil level at planting to encourage basal shoot production and recovery from clematis wilt. Water deeply once weekly during the first two growing seasons in the absence of rain; established plants tolerate brief dry periods, with flower production decreasing under sustained drought. A 2-3 inch (5-8 cm) layer of shredded leaf or compost mulch maintains cool root-zone temperatures; the crown itself is left mulch-free to limit rot. Clematis wilt may collapse one or more stems in years 1-3; cutting affected stems to ground level typically allows regrowth from the crown. Powdery mildew develops on foliage in humid summers with poor air circulation. A balanced fertilizer applied in early spring as buds break supports the first flush.

Pruning

Pruning Group 2 (light pruning). In late winter or early spring before bud break, dead and weak stems are removed and remaining stems are lightly trimmed back to a strong pair of buds. After the first flush of flowers in June, spent flowering stems are cut back by one-third to one-half to encourage the second flush. Hard pruning in late winter sacrifices the double first-flush flowers, which form on previous season's wood.

Pruning Schedule

early springsummer