Honeysuckle 'Graham Thomas'

Sun

Full sun to partial shade; flowers best with good light on its stems and cool, shaded roots.

Water

Keep evenly moist while establishing. Once established, water deeply during prolonged dry spells, particularly beside walls and fences.

Soil

Moist but well-drained soil enriched with organic matter; tolerates clay, loam and sandy soil if neither waterlogged nor persistently dry.

Height

10-20 ft (3-6 m)

Spread

3-6 ft (0.9-1.8 m)

Flowers

Summer into early autumn; fragrant tubular flowers open creamy white and mature to rich yellow.

Foliage

Opposite pairs of oval, medium-green leaves; normally deciduous, though some leaves may persist in mild winters.

Growth

Fast once established.

Care needed

Medium

• Pollinators
• Wildlife
• Low allergen
• Fragrant

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   2 ft (0.6 m)

2. After 1 year

   3 ft (1.1 m)

3. After 2 years

   5 ft (1.5 m)

4. After 3 years

   6 ft (1.8 m)

   full size

About 3 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Mildly toxic: may upset a stomach

Native to

the UK

Invasive in

the US

Growth rate

Fast

• Provide a sturdy trellis, wires or an arch; the stems twine but cannot cling to a bare wall.
• Tie young shoots loosely to their support and spread them out to cover it evenly.
• Water deeply during the first growing season and during later droughts.
• Apply a 2-3 in (5-8 cm) organic mulch in spring, keeping it clear of the main stems.
• On poor soil, apply a balanced fertiliser in spring; avoid heavy nitrogen feeding, which encourages leaves rather than flowers.

Pruning. After the main flowering flush in late summer or early autumn, shorten overlong flowered shoots and thin congested stems, leaving some fruiting growth for birds. Renovate a badly tangled plant by cutting it back hard in late winter, accepting reduced flowering that year.

Late winter

Check supports and remove dead or damaged stems; carry out hard renovation only if needed.

Spring

Plant while the soil is workable, water thoroughly and apply mulch.

Late spring

Tie in new shoots and check their soft tips for aphids.

Summer

Water during dry spells and guide wandering stems back onto their support.

Late summer

After the main flush, shorten excessive growth and thin crowded stems.

Autumn

Leave some berries for birds and remove unwanted seedlings.

• Train over an entrance arch to bring evening fragrance close to a frequently used path.
• Cover a fence or trellis behind a mixed border, with lower plants shading the root area.
• Grow over a sturdy pergola beside an evening seating area.
• Combine with a climbing rose on a broad support for overlapping flowers and a loose cottage-garden effect.
• Train along the edge of a wildlife garden, keeping it out of small trees and shrubs that it could overwhelm.

Garden styles it suits: English country, Cottage garden, Romantic rose garden, Wildlife garden, Sensory garden and Evening garden.

Plant it with: Climbing roses, Hardy geraniums, Lady's mantle, Foxgloves, Astrantia and Japanese anemones.

Wildlife: Fragrant flowers provide nectar for moths and bees. Birds eat the red berries, and mature tangled growth can provide shelter and nesting cover.

• Aphids can distort young shoots: wash off small colonies with water and encourage ladybirds and other predators.
• Powdery mildew is more likely with dry roots and crowded growth: water deeply, mulch and thin stems to improve airflow.
• Leaf scorch and premature leaf fall often follow drought, especially beside walls: soak the root zone rather than giving frequent shallow watering.
• A bare base or tangled mass of stems develops without training: spread out young shoots and periodically remove a few old stems near ground level.

Berries can cause stomach upset, vomiting and diarrhoea if eaten by people, cats or dogs; do not treat them as edible fruit. Keep foliage and stems out of pets' reach as well. Toxicity to horses is not well established, so keep this climber away from grazing areas.

Where it spreads. European honeysuckle can escape cultivation and spread by bird-sown seed in parts of the Pacific Northwest of the United States. It is not Japanese honeysuckle, but check local guidance before planting near natural woodland and remove unwanted seedlings.

• Japanese honeysuckle (Lonicera japonica)

  Usually bears flowers in pairs along the stems and produces black berries; 'Graham Thomas' has clustered flowers near shoot tips and red berries. Japanese honeysuckle is invasive in many regions.

• Italian honeysuckle (Lonicera caprifolium)

  Its upper leaf pairs join around the stem to form a conspicuous disc beneath the flowers; the leaves of 'Graham Thomas' remain separate.

Lonicera honours the botanist Adam Lonitzer, and the cultivar name honours British horticulturist Graham Stuart Thomas.

Propagation. Layer a low-growing stem in spring, or take semi-ripe cuttings in summer. Use vegetative propagation to retain the cultivar; seedlings will not reliably match 'Graham Thomas'.

Accepted botanical name

Lonicera periclymenum

In the US and Canada

Introduced in Canada and the lower 48 states.

Native range

Albania, Austria, Belgium, Corse, Denmark, France, Germany, Great Britain, Greece, Ireland, Italy and Morocco.

Measured

Soil pH 5 to 5.5. Average height 350 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.