Introduction

Lonicera periclymenum "Graham Thomas" (Graham Thomas Honeysuckle) is a deciduous climber in the Caprifoliaceae family, reaching 5 metres with white aging yellow flowers in summer. Hardy in USDA zones 5-9. Valued for its fragrant flowers.

Lonicera periclymenum "Graham Thomas", commonly known as Graham Thomas Honeysuckle, is a deciduous deciduous climber in the Caprifoliaceae family. The plant reaches 5 metres in height with a spread of approximately 2.5 metres, climbing by means of twining stems that spiral around supports. The white aging yellow flowers appear in summer, providing seasonal colour. The flowers emit a delightful fragrance that carries well in still air, making this an excellent choice near seating areas and pathways. Ornamental seed heads or fruit follow the flowers, extending the season of interest well into autumn and winter. The foliage is green, turning colour or dropping in autumn. Growth rate is fast-growing, capable of adding 1-2 metres of new growth per season. Native to England, this species has become a valued ornamental plant in temperate and subtropical gardens worldwide.

Botanical Description

Classification: Caprifoliaceae > Lonicera > periclymenum. The Caprifoliaceae (honeysuckle family) includes both climbing and shrubby species, many valued for fragrant flowers. This species is native to England and was introduced to European gardens from England. The genus Lonicera contains numerous species, many of which are valued in horticulture for their climbing habit and ornamental qualities.

Climbing Mechanism

Lonicera periclymenum "Graham Thomas" climbs by twining stems that spiral around supports. The growing tips actively rotate in a circular motion (nutation) seeking out vertical supports to wrap around. Once the stem contacts a suitable support, it begins spiraling upward. This mechanism works best with thin vertical supports such as wires, poles, string, or other plant stems. The stems cannot grip flat surfaces or very thick posts. The plant reaches approximately 5 metres under good growing conditions.

Group Climbing Guide — Honeysuckle

Vigorous twining habit. Will wrap around any vertical support. Can girdle small trees if unchecked.

Planting Guide

Step 1 — Site Selection: Choose a position in full sun to partial shade (4-6+ hours sunlight) with well-drained soil. Consider the mature size (5m tall × 2.5m wide) when selecting the site. Step 2 — Support Installation: Install a fence, post-and-wire system, or open lattice before planting. Ensure the support is rated for the mature weight of the plant. Step 3 — Soil Preparation: Dig a hole twice the width and 1.5 times the depth of the rootball. Mix in well-rotted compost and a slow-release fertilizer. Target pH 5.5-7.0. Step 4 — Planting: Plant at the same depth as the container (except clematis, which should be planted deeper). Water thoroughly and firm in gently. Step 5 — Aftercare: Mulch with 5-8 cm of organic matter. Water regularly during the first growing season. Guide initial stems toward the support using soft ties. Protect from slugs and snails in the early stages.

Climate & Hardiness

Spring: Apply a balanced slow-release fertilizer as new growth begins. Mulch around the base with organic matter. Tie in new stems to supports. Check for winter damage and prune out any dead or damaged growth. Summer: Water regularly , especially during dry spells. Feed monthly with a liquid fertilizer during the growing season. Continue training and tying in new growth. Deadhead if applicable. Autumn: Reduce watering and feeding as growth slows. Apply a thick mulch to protect roots from winter cold. In colder zones, consider wrapping the crown with fleece or straw. Winter: This species is reliably hardy in most temperate gardens. Check ties and supports. Plan any structural pruning for late winter.

Overwintering Guide

Hardy. Evergreen types may lose some leaves in severe cold. Mulch young plants. No winter pruning.

Propagation

Stem cuttings (primary method): Take semi-ripe cuttings in mid to late summer (July-August). Select healthy, current season's growth, cutting just below a leaf node. Cuttings should be 10-15 cm long. Remove lower leaves, dip the cut end in hormone rooting powder, and insert into a well-drained mix of perlite and peat (50:50). Place in a propagator or cover with a clear plastic bag. Bottom heat of 18-21°C improves success rates. Roots typically develop within 4-8 weeks. Success rate: 60-80%. Layering (alternative): In spring, select a low-growing flexible stem. Wound the underside lightly, pin it to the ground with a wire staple, and cover with soil. Keep moist. Roots develop over 6-12 months. Sever from the parent plant and transplant the following season. Success rate: 80-90%.

Pests & Diseases

Common Problems

Group Disease & Pest Reference (Honeysuckle)

• Powdery mildew — very common in dry conditions; ensure roots stay moist while foliage has air flow
• Aphids — cluster on shoot tips causing distortion; blast with water, encourage predators
• Leaf spot — fungal spots in wet seasons; mostly cosmetic; improve air circulation
• Leaf blight — browning and dieback of shoots; prune out affected growth
• Honeysuckle moth caterpillar — larvae feed inside rolled leaves; hand-pick affected leaves

Training & Pruning

Pruning timing: Prune late winter. Formative pruning: In the first 2-3 years, focus on building a strong framework of main stems by selecting well-placed shoots and tying them to the support. Remove weak, crossing, or badly-placed stems. Maintenance pruning: Once established, shorten side shoots after flowering to maintain shape and encourage new flowering wood. Remove any dead or damaged growth promptly. Thin overcrowded stems to maintain good air circulation. Training: Tie in new growth regularly throughout the growing season using soft garden twine or plant clips. Spread stems evenly across the support for the best coverage and flowering display. Check ties annually and replace any that are too tight.

Pruning Guide — Honeysuckle

Prune after flowering by cutting back flowered shoots to strong buds. Every 3–4 years renovate by cutting to base.

Support Structures

Best support types for Lonicera periclymenum "Graham Thomas": Primary recommendation: A fence, post-and-wire system, or open lattice, sized to accommodate the mature height of 5m and spread of 2.5m. Wire systems: Horizontal galvanized wires at 30-45 cm intervals, tensioned between vine eyes or posts. Ideal for walls and fences. Trellis panels: Choose panels with openings suited to the climbing method — thin supports for tendrils or stems to wrap around. Installation tips: Mount supports at least 5 cm from the wall for air circulation. Use stainless steel or galvanized fittings to prevent rust. Ensure all fixings are rated for the mature weight of the plant, especially in exposed positions.

Support Guide — Honeysuckle

Posts, pergolas, wire fences, through hedges. Tolerant of most support types. Sturdy enough for vigorous growth.

Wildlife Value

Lonicera periclymenum "Graham Thomas" is highly attractive to hummingbirds, which are drawn to the tubular flowers rich in nectar. The plant also benefits bees, butterflies, and other pollinating insects. The dense foliage provides nesting cover for small birds. Ecosystem services: Provides nectar, pollen, shelter, and nesting sites. The climbing habit creates vertical habitat layers, increasing garden biodiversity. The fruit/seed heads provide winter food for birds.

Landscape Design

Walls and fences: Lonicera periclymenum "Graham Thomas" is well-suited to covering walls and fences when provided with suitable support structures. Pergolas and arbors: Excellent choice for pergolas, creating a dramatic overhead canopy. Screening: Creates seasonal screening (summer privacy) when grown on appropriate support. Effective for disguising unsightly structures, dividing garden rooms, or creating private spaces. Feature plant: Makes a stunning focal point when grown on a prominent support structure. Combine with other climbers for a layered, naturalistic effect.

History & Culture

Honeysuckle has deep roots in European folklore, associated with love, devotion, and fidelity. Shakespeare mentions it in A Midsummer Night's Dream. The sweet evening fragrance has made it a cottage garden favourite for centuries. In traditional herbal medicine, honeysuckle flowers were used for respiratory ailments.

Container Growing

Lonicera periclymenum "Graham Thomas" is not recommended for container growing due to its vigorous root system and large mature size (5m). The plant requires open ground to develop a sufficiently large root system for healthy growth and flowering. If space is limited, consider a more compact cultivar or alternative species better suited to container culture.

Frequently Asked Questions

Seasonal Care Calendar