Japanese holly

Sun

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

Water

Keep the root zone evenly moist but not waterlogged. Established plants tolerate brief dry spells, but prolonged drought can cause leaf drop.

Soil

Moist, well-drained, acidic soil rich in organic matter. Alkaline soil often causes yellow leaves, and poorly drained clay encourages root rot.

Height

5-10 ft (1.5-3 m); cultivar sizes vary considerably

Spread

5-8 ft (1.5-2.4 m); narrow and dwarf cultivars spread much less

Flowers

Small, inconspicuous white flowers in late spring to early summer. Female plants can produce small black berries if a compatible male holly flowers nearby.

Foliage

Evergreen. Small, alternate, glossy dark green leaves with finely rounded teeth along the edges.

Growth

Slow to moderate

Care needed

Medium

• Water deeply during the first growing season whenever the upper soil begins to dry.
• Apply 2-3 in (5-8 cm) of organic mulch, keeping it clear of the stems.
• Test soil pH if leaves turn yellow; correct alkaline conditions rather than repeatedly adding general fertilizer.
• Feed lightly in spring only if growth is weak or a soil test indicates a deficiency.
• Shelter plants from drying winter winds, especially near the cold end of their range.

Pruning. Prune in late winter or early spring to remove dead wood and reduce size, cutting back to leafy side shoots. Lightly clip hedges after the spring growth flush, keeping the base wider than the top; avoid heavy pruning late in the growing season.

Late winter

Remove dead, damaged or crossing branches and make any necessary size reductions.

Spring

Plant when the soil is workable, water thoroughly and mulch the root zone.

Spring

Check new leaves for yellowing and test soil pH before treating.

Early summer

Lightly clip hedges or topiary after the first flush of growth.

Summer

Water during prolonged dry weather and inspect foliage for mites or scale.

Autumn

Check soil moisture before winter, especially around newly planted shrubs and containers.

Winter

Protect exposed container plants from severe freezes and drying winds.

• Clip into low hedges around paths or formal beds where the soil is acidic and well drained.
• Use rounded forms beside grasses and ferns to contrast solid evergreen shapes with softer foliage.
• Plant narrow upright cultivars as vertical accents in small courtyards or beside entrances.
• Train into cloud-pruned forms or simple topiary for Japanese-inspired and formal gardens.
• Grow compact cultivars in large, well-drained containers for year-round structure.

Garden styles it suits: Japanese, Zen dry garden, Formal, Topiary garden, Modern courtyard and Green on green.

Plant it with: Japanese maple, Azalea, Camellia, Japanese forest grass, Hosta and Japanese painted fern.

Wildlife: The small flowers attract bees and other insects. Birds may eat the black berries, and dense shrubs provide shelter; frequent clipping reduces flowering and fruiting.

• Yellow leaves with greener veins usually indicate iron deficiency associated with alkaline soil. Test the soil, address the pH and use chelated iron only as a temporary correction.
• Root rot, including black root rot, can cause yellowing, wilting and branch death. Improve drainage, avoid overwatering and remove badly affected plants.
• Spider mites can cause pale stippling and bronzed foliage, especially in hot, dry conditions. Rinse foliage and use an approved insecticidal soap or horticultural oil if needed.
• Scale insects can weaken growth and produce sticky honeydew. Prune out heavily infested shoots and apply a locally approved horticultural oil at the appropriate stage.

Treat the berries and leaves as toxic to people, cats, dogs and horses if eaten. They contain saponins and can cause vomiting, diarrhoea and abdominal discomfort; small accidental ingestions usually cause gastrointestinal illness rather than severe poisoning. Keep berries away from children and pets, and seek medical or veterinary advice after ingestion.

• Common box (Buxus sempervirens)

  Box has opposite pairs of leaves with smooth margins; Japanese holly has alternate leaves with finely rounded teeth.

• Inkberry (Ilex glabra)

  Inkberry usually has larger, more elongated leaves, with teeth mainly near the tips rather than along most of the margins.

• Japanese privet (Ligustrum japonicum)

  Japanese privet has much larger leaves in opposite pairs and conspicuous clusters of white flowers; Japanese holly has small alternate leaves and tiny flowers.

The epithet crenata means scalloped, referring to the rounded teeth on the leaf margins, while Japanese holly refers to its native occurrence in Japan.

Propagation. Take semi-ripe cuttings in late summer and root them in a moist, free-draining medium under cover. Seed is slow to germinate and does not reliably reproduce named cultivars; check plant breeders' rights or patent restrictions before propagating protected cultivars.

Accepted botanical name

Ilex crenata

In the US and Canada

Introduced in the lower 48 states.

Native range

Assam, China North-Central, China South-Central, China Southeast, East Himalaya, Hainan, Japan, Korea, Kuril Is., Myanmar, Nepal and Sakhalin.

Measured

Soil pH 4.5 to 5.5. Average height 305 cm.

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