Evergreen climbing hydrangea

Evergreen climbing hydrangea: how do you recognise it?

Habit

Self-clinging climber with aerial roots, 5–6 m tall and up to 3 m wide; slow growing in its first years.

Leaves

Leathery, glossy dark green, elliptic to ovate, 8–15 cm; evergreen.

Flowers

Flat flowerheads of small cream-white flowers surrounded by larger white outer flowers. July–August.

Roots

Aerial roots along the stems provide the grip; the true roots are shallow.

Flowering: July–August · Plants: April–May and September · Pruning: May and August

Why grow it?

• Evergreen: a glossy wall of leaves even in winter.
• Climbs by itself with aerial roots, without wires, to about 6 m.
• Flowers in summer (July–August) with flat, white flowerheads that attract bees.
• Does well in half shade and shade, where few climbers flower freely.
• Low maintenance: hardly any pruning.

Evergreen climbing hydrangea: where does it grow best?

• Half shade to shade against a sheltered wall or tree trunk; not in strong midday sun.
• Humus-rich, moisture-retentive but well-drained soil: sand or loam, acid to neutral; normal to moist.
• Sheltered from cold wind. Avoid a spot where frozen leaves are hit by direct sun in the morning, as this scorches the foliage.
• Plant 30–40 cm from the wall; allow 2–3 m of width.
• A rough wall or bark helps it cling; on a smooth wall a light support is handy.

Light

Partial shade and shade

Soil type

Sand or loam

Acidity

Acid or neutral

Moisture

Normal or wet

Size

6 m tall, 3 m wide

Hardiness

Half hardy (to -12 °C): protect it in harsh winters

Goes well with

• Hosta: Large leaves at the base, in the same shade.
• Ferns: Fresh, green underplanting for the shade.
• Hellebore: Evergreen and flowering in winter in front of the wall.
• Bergenia: Evergreen with firm leaves and pink flowers in spring at the base.

Evergreen climbing hydrangea: when and how to plant it?

Plant in April–May and September.

1. Plant in April–May or in September, when the soil is not frozen; in spring the plant has the whole summer to root.
2. Dig a hole twice as wide as the root ball, 30–40 cm from the wall, and mix in compost.
3. Set the plant slightly angled towards the wall, at the same depth as in the pot.
4. Tie the first shoots loosely to a support or wire until the aerial roots grip; this takes a year or two.
5. Water generously straight away, even if it is raining.
6. Spread a 5 cm layer of leaf mould round the base and keep the soil moist for the first few years.

Care

Water

In the first 2–3 years weekly in dry weather; later during long dry spells. Soil beside a wall dries out quickly.

Feeding

In April compost or organic fertiliser for shrubs.

Mulching

Each spring a layer of leaf mould; in November an extra layer if hard frost is forecast.

Patience

It grows slowly in the first years and flowers only after a few years: that is normal.

Tying in

Tie in loose shoots until they cling by themselves.

Tip: Plant it against a rough surface and tie the first shoots in loosely: the aerial roots only grip after a year or two. In the first winters, spread a thick layer of mulch round the base.

Evergreen climbing hydrangea: when to prune it?

Pruning months: May and August.

When: Hardly needed. Trim lightly after flowering, in August, and remove frosted shoots in May.

How:

• After flowering, shorten long, hanging shoots to the desired shape.
• In May, when new growth starts, cut dead or frosted stems back to healthy wood.
• Remove dead and thin stems from the centre.
• Keep it away from gutters and windows.

Caution: Do not prune hard in winter or early spring: it flowers on older wood, so you would lose flowers.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Semi-ripe cuttings

July–August: 10–15 cm cuttings with a small piece of old wood (heel) in sandy compost under plastic. Roots in 6–8 weeks.

Layering

In spring lay a long shoot in the soil and peg it down; separate it after a year.

Evergreen climbing hydrangea: how does it get through the winter?

Hardy to −12 °C: protect in harsh winters.

• Moderately hardy, to about −12 °C. In hard Belgian winters the foliage may freeze; protect it.
• In November spread a thick layer of mulch (10 cm) round the base and cover with fleece or hessian in severe frost.
• In cold east winds hang a screen of hessian or fleece in front of the plant.
• If it does freeze, prune only in May: it often shoots again from the base.

Diseases and pests

• Frosted foliage: Brown, limp leaves after hard winters. Wait until May to cut away the frosted parts; protect it better the next winter.
• Yellow leaves: On chalky or too wet soil the leaves may turn yellow. Use acid compost and improve drainage.
• Slugs: Young shoots are eaten in spring. Collect them in the evening.
• Aphids: On young shoots in May. Rinse off with water or let ladybirds do the work.

Through the year

• January: Rest. Check the protection during frost.
• February: Check for winter damage.
• March: Give compost. Remove any covering.
• April: Plant. Feed. Mulch.
• May: Plant. Cut away frosted shoots. Tie in loose shoots.
• June: Water in dry weather.
• July: Flowering, bees. Water in dry weather.
• August: Flowering. Trim lightly after flowering. Take cuttings.
• September: Plant. Look after cuttings.
• October: Prepare winter mulch.
• November: Mulch round the base. Have fleece ready.
• December: Rest. Cover in severe frost.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• Unlike the common climbing hydrangea, this species is evergreen; it comes from the mountain forests of Mexico.
• Climbing hydrangeas cling with aerial roots and climb trees and walls without wires.
• The large outer flowers of the flowerhead are sterile: they lure insects to the small, fertile flowers.