Foam of May

Foam of May: how do you recognise it?

Habit

Dense, rounded shrub about 1.5 m tall and wide, with slender, brown, arching stems.

Leaves

Narrow and lance-shaped, 2–4 cm long, finely toothed towards the tip, fresh green; sometimes yellow in autumn.

Flowers

Pure white flowers less than 1 cm across in small clusters along the entire length of the stems, in April–May.

Flowering wood

Flowers on the previous year’s stems: the flower buds form in summer.

Roots

Fibrous and fairly shallow: easy to move, but sensitive to long droughts.

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

Why grow it?

• One of the earliest flowering shrubs: a white cloud in April.
• Graceful, arching stems that look light and airy even when not in flower.
• Early nectar and pollen for bees.
• Fully hardy and easy in any ordinary soil.
• Suitable as a specimen, in a mixed border or in an informal flowering hedge.
• Flowering stems look lovely in a spring bouquet.

Foam of May: where does it grow best?

• Sun to partial shade; it flowers best in sun.
• Any ordinary garden soil: sand, loam or clay, acid to chalky.
• Moderately moist and well-drained: no prolonged waterlogging and no bone-dry spot.
• Give it room so the stems can arch freely: allow 1.5 m per plant, in a hedge 60–80 cm.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

1.5 m tall, 1.5 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Grape hyacinth: A blue carpet beneath the white stems in April.
• Tulip: White or pink tulips flower at the same time and fill the base.
• Forget-me-not: Sky-blue flowers that seed themselves around under the shrub.
• Flowering currant: Flowers at the same time, with pink to red clusters beside the white cloud.

Foam of May: 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 neither frozen nor waterlogged.
2. Dig a hole twice as wide as the root ball and loosen the bottom.
3. Mix a few spadefuls of compost into the soil you dug out.
4. Set the shrub at the same depth as in the pot and firm the soil well.
5. Water in thoroughly straight away.
6. Spread a mulch of compost or wood chips around the base.

Care

Water

Regularly in dry spells during the first year. After that, only in long dry periods, especially in July, when the flower buds are forming.

Feeding

In March or after pruning, a spadeful of compost or some organic fertiliser for flowering shrubs.

Mulching

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

Spent flowers

These are removed when you prune after flowering.

Shape

Do not clip it into a tight ball or formal hedge: its natural, arching shape is its charm.

Tip: Always prune it straight after flowering, at the end of May, and keep the long young shoots: they carry next year’s flowers.

Foam of May: when to prune it?

Pruning months: May.

When: Straight after flowering, at the end of May. It flowers on the previous year’s wood.

How:

• Cut flowered stems back to a strong, young side shoot lower down.
• Every year, remove a quarter to a third of the oldest stems right at the base.
• Keep the long young shoots: they will flower next spring.
• An old, neglected shrub can be cut back to 20–30 cm straight after flowering; it will flower less the following year.

Caution: Do not prune in winter or early spring: you would cut off the flower buds.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Softwood cuttings

In June: cuttings of 8–10 cm from young, non-flowering shoots, lower leaves removed, in moist cutting compost under plastic. Roots form within a few weeks.

Hardwood cuttings

In November–December: 20 cm lengths of ripe stems, pushed two thirds into the soil in a sheltered spot. Transplant after a year.

Layering

In spring, peg a low stem into the soil; sever it a year later.

Foam of May: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy to about −30 °C: no protection needed.
• A late night frost may brown open flowers; buds that are still closed open normally.
• In a pot: stand it against a wall and wrap the pot in hessian in hard frost.

Diseases and pests

• Aphids: On young shoots in May–June. Ladybirds and birds usually deal with them; otherwise hose them off with water.
• Few flowers: Usually caused by pruning in winter or early spring, or by too much shade. From now on, prune only straight after flowering.
• Bare and tangled: An old shrub becomes bare at the base and full of dead wood. Remove a few old stems at ground level each year.
• Drought: Brown leaf edges and early leaf drop in a dry summer. Water and mulch the soil.

Through the year

• February: Do not prune: the flower buds are already on the stems.
• March: Plant. Add compost.
• April: Flowering: a white cloud of tiny flowers. Cut stems for the vase.
• May: Last flowers. Prune straight after flowering.
• June: Take softwood cuttings. Water in dry spells.
• July: Water in dry spells: the new stems are forming flower buds.
• October: Plant. Sometimes yellow autumn leaves.
• November: Plant. Take hardwood cuttings.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• The name Spiraea comes from the Greek speira, meaning ‘wreath’ or ‘coil’.
• ‘Arguta’ means ‘sharp’ and refers to the finely toothed leaves.
• It is called foam of May or bridal wreath because its white, arching stems recall sea foam or a bridal garland.