Japanese snowball

Sun

Full sun to partial shade; afternoon shade helps in hot summers.

Water

Keep the root zone evenly moist but not waterlogged; established plants still need deep watering during prolonged dry spells.

Soil

Humus-rich, well-drained soil, preferably slightly acidic to neutral; tolerates clay if drainage is adequate.

Height

8-15 ft (2.4-4.6 m)

Spread

10-15 ft (3-4.6 m)

Flowers

White flowers in late spring to early summer, in rounded snowballs or flat lacecap-like heads, depending on the form.

Foliage

Opposite, oval, toothed leaves with deeply impressed veins; green in summer, often turning burgundy, red or purple in autumn.

Growth

Moderate

Care needed

Low

• Water deeply during the first two growing seasons and whenever established plants experience prolonged drought.
• Spread 2-3 in (5-8 cm) of organic mulch over the root zone, keeping it clear of the stems.
• Top-dress with compost in spring; use a balanced fertiliser only if growth is weak and soil fertility is low.
• Allow space for the mature spread so the layered branches do not need repeated cutting back.
• Avoid exposed, hot sites where the soil dries out quickly.

Pruning. Prune immediately after flowering, removing dead, damaged or crossing branches and cutting selected old stems back to the base if renewal is needed. Avoid shearing or routine winter pruning, which spoils the branching pattern and removes flower buds.

Early spring

Check for winter damage and refresh the mulch without burying the stem bases.

Spring

Top-dress with compost and water newly planted shrubs during dry weather.

Late spring

Enjoy the flowers and inspect young shoots and leaf undersides for aphids or feeding damage.

Early summer

After flowering, carry out any necessary thinning or size reduction.

Summer

Water deeply in dry spells; take softwood cuttings from healthy, non-flowering shoots.

Autumn

Plant while the soil is workable and moist; in very cold districts, wait until spring.

• Use as a specimen in a lawn or broad bed where its branching shape can be seen from several sides.
• Place at a woodland edge with ferns, hostas and Japanese maples for contrasting foliage and autumn colour.
• Plant behind lower perennials in a mixed border, allowing enough space for the wide canopy.
• Use snowball-flowered forms in a white garden; use doublefile forms where horizontal branch lines are part of the design.

Garden styles it suits: Japanese, Woodland, English country, Traditional, White garden and Autumn colour.

Plant it with: Japanese maple, Hosta, Japanese painted fern, Astilbe, Oakleaf hydrangea and Epimedium.

Wildlife: Fertile doublefile forms provide flowers for visiting insects and red fruits that ripen black and are eaten by birds. Rounded snowball forms are sterile and offer little pollen, nectar or fruit, although their branches still provide cover.

• Drought stress and leaf scorch: water the root zone deeply, maintain mulch and provide afternoon shade in hot districts.
• Aphids on young shoots: wash off small colonies with water and encourage natural predators; use insecticidal soap if necessary.
• Viburnum beetle, where present: inspect damaged foliage for larvae and remove infested shoots or treat young larvae with a locally approved control.
• Poor flowering: avoid winter pruning, excessive nitrogen feeding and deep shade; flowers develop on older wood.

Not known to be toxic to people, cats, dogs or horses, although species-specific safety information is limited. Do not treat the leaves or fruit as food; eating plant material may cause stomach upset.

Where it spreads. Fertile doublefile forms can self-seed and have escaped cultivation in parts of the eastern United States, including the Mid-Atlantic region. Check local invasive-plant guidance before planting; sterile snowball forms do not spread by seed.

• European snowball bush (Viburnum opulus 'Roseum')

  It also has rounded white flower heads, but its leaves are distinctly three-lobed rather than oval with deeply impressed veins.

• Chinese snowball (Viburnum macrocephalum)

  It usually has larger snowball flower heads and a coarser, more upright habit, without the characteristic tiered branching of doublefile Japanese snowball.

• Smooth hydrangea (Hydrangea arborescens)

  Its flower heads appear mainly in summer on new shoots; its leaves are generally broader and lack the strongly pleated appearance of Japanese snowball.

The botanical name plicatum means pleated or folded, referring to the strongly veined leaves, while snowball describes the rounded flower heads of the sterile forms.

Propagation. Take softwood cuttings in early summer or semi-ripe cuttings later in summer; layering a low branch is another option. Seed is possible only from fertile forms, can be slow to germinate and does not reliably reproduce named cultivars.

Accepted botanical name

Viburnum plicatum

In the US and Canada

Introduced in the lower 48 states.

Native range

China North-Central, China South-Central, China Southeast, Japan and Taiwan.

Measured

Average height 300 cm.

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