Buttonbush

Buttonbush: how do you recognise it?

Habit

Loose, rounded shrub about 2 m high and wide, with upright and slightly spreading branches.

Leaves

Oval to lance-shaped, 7–15 cm, glossy dark green; opposite or in whorls of three. Late to leaf out, often not until May. Deciduous.

Flowers

Spherical heads 2.5–4 cm across, packed with small white to creamy tubular florets with protruding styles, in July–August.

Scent

Sweet and light; strongest on warm summer days.

Fruit

Hard, round brown balls made up of small nutlets, which hang on into winter.

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

Why grow it?

• Grows in wet soil and at the pond edge, where few shrubs survive.
• Striking white pincushion-like flower balls in July–August.
• A real butterfly magnet; bees and bumblebees also visit the scented flowers.
• The round brown fruit heads stay on the branches into winter.
• Very hardy and easy: one prune in March is enough.

Buttonbush: where does it grow best?

• Sun or partial shade; it flowers most freely in full sun.
• Humus-rich soil: sand, loam, clay or peat, acid to neutral. Preferably avoid chalky soil.
• Moist to wet: at a pond edge, in a ditch or where water lies. Its base can stand in shallow water.
• It dislikes drying out: avoid dry, sunny sandy soil unless you water.
• Allow 1.5–2 m per plant.

Light

Sun and partial shade

Soil type

Sand, loam, clay or peat

Acidity

Acid or neutral

Moisture

Normal or wet

Size

2 m tall, 2 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Purple loosestrife: Purplish-pink spikes in the same summer, in the same wet soil.
• Hemp agrimony: Pink flower heads for butterflies at the water’s edge.
• Meadowsweet: Creamy, fragrant plumes in moist soil.
• Red-barked dogwood: Red winter stems to keep the bare shrub company in winter.

Buttonbush: when and how to plant it?

Plant in March–April and October–November.

1. Plant in March–April or October–November, when the soil is not frozen.
2. Dig a hole twice as wide as the root ball and mix in compost or leaf mould.
3. Set the plant at the same depth as in the pot; by a pond, the base can sit on the bank or in shallow water.
4. Firm the soil well and water generously, even in wet soil, so the earth settles around the roots.
5. Mulch with leaf mould to keep the soil moist.

Care

Water

In a moist spot, extra water is rarely needed. In ordinary garden soil, water generously in dry summers.

Feeding

In March, after pruning, some compost or organic fertiliser. Do not feed right next to a pond, to avoid algae.

Mulching

A layer of leaf mould in spring keeps the soil moist.

Patience in spring

It leafs out very late. If there are no leaves in April, wait until late May before giving up on it.

In a pot

Can be grown in a large pot without a drainage hole or standing in a saucer of water, so the compost always stays wet.

Tip: Give it the wettest spot in the garden, such as a pond edge or a hollow where rainwater collects: that is where it flowers best and needs hardly any care.

Buttonbush: when to prune it?

Pruning months: March.

When: In March, before growth starts. It flowers on new wood, so spring pruning costs no flowers.

How:

• Cut frosted or dead shoot tips back to healthy wood; in hard frost the tips often die back a little.
• Shorten the shoots by a third for a compact shrub with plenty of flowers.
• Every few years you can rejuvenate it by cutting it back to 30–60 cm above the ground.
• Remove thin, weak and crossing stems at the base.

Caution: Do not prune in summer: you would remove the flower buds.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Softwood cuttings

In June–July, 10 cm cuttings from young shoots, in moist cutting compost under plastic. They root quickly.

Hardwood cuttings

In winter, push 20 cm lengths of this year’s shoots into moist soil or a pot of wet sand. They shoot in spring.

Seed

Sow in spring on moist seed compost and keep it wet. Seedlings flower after two to three years.

Buttonbush: how does it get through the winter?

Hardy to −30 °C.

• Very hardy, to about −30 °C: no protection is needed in Belgium.
• In severe winters the shoot tips may die back; cut them off in March and the shrub will reshoot.
• The brown fruit balls stay on the bare branches and decorate the winter garden.
• In a pot: wrap the pot in hessian or stand it against a wall so the roots do not freeze.

Diseases and pests

• Late leaves: In April it is still bare. No problem: it does not leaf out until May. Scratch a twig with your fingernail; if it is green, it is alive.
• Dieback: After hard frost the shoot tips are dead. Cut back to healthy wood in March; it flowers normally on the new growth.
• Drought: Drooping, browning leaves and few flowers in a spot that is too dry. Water generously or move it somewhere wetter.
• Aphids: On young shoots. Ladybirds usually deal with them; otherwise hose them off.

Through the year

• March: Prune: shorten by a third or cut back to 30–60 cm. Add compost.
• April: Plant. Be patient: it leafs out late.
• May: New leaves appear. Apply mulch.
• June: Take softwood cuttings. Water in dry weather.
• July: White flower balls. Butterflies and bees.
• August: In flower. Water in dry weather.
• September: The fruit balls turn brown.
• October: Plant. Yellow autumn colour.
• November: Plant.
• December: Take hardwood cuttings. Fruit balls decorate the bare branches.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• The name Cephalanthus comes from the Greek words for ‘head’ and ‘flower’, after the spherical flower heads.
• It belongs to the same plant family as coffee, the madder family.
• In its native habitat, ducks and other waterbirds eat the seeds from the fruit balls.