Hoary willow

Hoary willow: how do you recognise it?

Habit

Broad, loose shrub 3–4 m tall and wide, with slender, flexible, red-brown twigs.

Foliage

Narrow, linear to lance-shaped, 6–12 cm long; dark green above, silvery-white and felted beneath, with slightly rolled margins.

Flower

Slender yellow catkins in April, appearing with the leaves. Male and female flowers are on different plants.

Fruit

Small capsules with seeds bearing white, downy fluff, dispersed by wind in spring.

Roots

Dense and wide-spreading: they seek water and may find pipes and foundations.

Flowering: April · Plants: March–April and October–November · Pruning: March

Why grow it?

• Silvery-grey, lavender-like foliage that looks light and airy and contrasts nicely with dark shrubs.
• Catkins in April that give early nectar and pollen to bees and other insects.
• Tolerates chalk and temporary drought better than most willows.
• Grows quickly and is easy to renew by cutting back.
• Suitable for an informal hedge, a natural bank or a large mixed shrub border.

Hoary willow: where does it grow best?

• Sun to partial shade; in sun the foliage stays more silvery.
• Ordinary garden soil, even gravelly or chalky: sand, loam or clay, acid to chalky.
• Normal to moist; it tolerates drought better than most willows, but grows best with regular moisture.
• Hardy and wind-tolerant; the flexible branches rarely break.
• Allow 3–4 m per plant, and at least 4–5 m from the house, sewers and drains.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal or wet

Size

4 m tall, 4 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Red-barked dogwood: Red twigs in winter beside the silvery willow.
• Purple loosestrife: Purple flowers in summer in a moister spot.
• Yellow flag iris: Yellow flowers at the water’s edge, in the same moist setting.
• Marsh marigold: Yellow spring flowers in the damp soil beneath the willow.
• Guelder rose: Together in a natural hedge with berries for birds.

Hoary willow: when and how to plant it?

Plant in March–April and October–November.

1. Plant in October–November or March–April, when the soil is neither frozen nor waterlogged.
2. Dig a hole twice as wide as the root ball and mix in a few spades of compost.
3. Set the plant at the same depth as in its pot or nursery and refill with the garden soil.
4. Leave 3–4 m between plants; for an informal hedge 1.5–2 m.
5. Water in generously straight away and firm the soil well.
6. Spread a layer of compost or bark mulch around the base.

Care

Water

In the first year, water generously once a week in dry weather. After that it copes, except in long dry summers.

Feeding

Little needed. A layer of compost in spring is enough.

Mulching

A layer of compost or bark in March keeps the soil moist and weed-free.

Renewal

Cut it back hard every 2–3 years to keep it compact and to get young, silvery-grey shoots.

Fallen leaves

Leave the leaves under the shrub in autumn as a natural mulch.

Tip: Cut it back hard in March every few years: it stays compact and gives young, silvery-grey shoots. Plant it at least 4–5 m from the house and from pipes.

Hoary willow: when to prune it?

Pruning months: March.

When: In March, before it leafs out. If you also want to enjoy the catkins, prune only half of the branches and do the rest after flowering.

How:

• Every 2–3 years, cut all branches back to 30–50 cm above the ground or to a pollard head.
• Remove dead, damaged and crossing branches completely.
• Cut suckers and weak shoots off at the base.
• A young shrub does not need pruning yet: let it develop its shape first.

Caution: If you cut it right back every year, you will get few catkins: they form on last year’s wood. A hard pruning therefore costs a year of flowers, so wait 2–3 years between hard prunings.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Hardwood cuttings

From November to February, take 25–30 cm cuttings of ripened branches and push the bottom 15 cm into moist soil. Willow cuttings root very easily; they can even root in water.

Seed

The seed stays viable for only a few days. Sow it as soon as it is ripe, in May–June, on moist soil; this is therefore not the easiest route.

Hoary willow: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy, down to about −30 °C: no protection is needed in Belgian winters.
• The bare, slender, red-brown twigs stay attractive in winter.
• It is less suited to a pot because it grows large and needs a lot of water; plant it in the open ground instead.

Diseases and pests

• Rust: Orange pustules under the leaves in summer. Clear affected leaves and keep the shrub airy.
• Aphids: Colonies on young shoots, sometimes with sticky honeydew. Wash them off with water or let ladybirds and hoverflies do the work.
• Willow leaf beetles: Small, shiny beetles and their larvae chew holes in the leaves. Pick them off and prune heavily infested branches.
• Root damage: The roots seek water and can block pipes. Plant it far from sewers, drains and the house.

Through the year

• March: Prune and plant. Apply compost.
• April: Flowering: catkins for bees. Plant.
• May: Prune after flowering if wanted. Water young plants.
• June: Watch for aphids. Water in dry weather.
• July: Dry spells: water young plants.
• September: Check for leaf beetles and rust.
• October: Plant. Leaves fall.
• November: Plant. Take cuttings.
• December: Rest. The bare twigs decorate the garden.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• The species name eleagnos points to its resemblance to Elaeagnus (oleaster), which also has silvery leaves.
• In nature it is a pioneer on gravel banks along rivers and can survive flooding and being buried in gravel.
• Willow catkins in early spring are an important source of pollen and nectar for bees and bumblebees.