Compacta Japanese holly

Sun

Full sun to partial shade; afternoon shade helps in hot climates. Shelter from drying winter winds, especially near its cold limit.

Water

Keep evenly moist while establishing. Once rooted, water during prolonged dry spells; avoid both waterlogged soil and repeated drying out.

Soil

Moist, well-drained, acidic soil rich in organic matter. Alkaline or chalky soil often causes yellow leaves and poor growth.

Height

4-6 ft (1.2-1.8 m), occasionally 8 ft (2.4 m) with age

Spread

4-6 ft (1.2-1.8 m), occasionally 8 ft (2.4 m) with age

Flowers

Small, inconspicuous creamy-white flowers in late spring to early summer.

Foliage

Evergreen. Small, glossy, dark green oval leaves with finely scalloped edges, arranged alternately along the stems.

Growth

Slow to moderate

Care needed

Medium

• Pollinators
• Wildlife
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   2.1 ft (0.65 m)

3. After 2 years

   2.7 ft (0.81 m)

4. After 3 years

   3 ft (0.96 m)

5. After 5 years

   4 ft (1.3 m)

About 7 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Invasive in

the US

Growth rate

Slow

• Plant with the root flare at soil level; improve drainage or use a raised bed on heavy, wet ground.
• Water deeply during dry weather through the first two growing seasons.
• Spread 2-3 in (5-8 cm) of organic mulch over the roots, keeping it clear of the stems.
• Apply a modest amount of slow-release fertiliser for acid-loving shrubs in spring only if growth is weak.
• Check soil pH before treating yellow foliage; iron supplements alone will not correct unsuitable soil.

Pruning. Prune in late winter or early spring before new growth, removing dead branches and shortening wayward shoots. Lightly trim hedges after the spring growth flush, keeping the base wider than the top; avoid heavy clipping late in the growing season.

Late winter

Remove dead or damaged stems and carry out any substantial shaping before new growth starts.

Spring

Plant where the soil is workable, water thoroughly and renew mulch.

Late spring

Check new leaves for yellowing and test soil pH if growth looks pale.

Early summer

Lightly clip hedges or rounded shapes after the first flush of growth.

Summer

Water during prolonged dry spells and inspect leaf undersides for spider mites.

Autumn

Water before the ground freezes if conditions are dry; stop clipping so new shoots can harden.

Winter

Protect container roots and shelter plants from drying winds in cold, exposed gardens.

• Clip into low hedges around beds or along paths for a neat evergreen boundary.
• Use rounded shrubs beside entrances or at border corners to repeat a simple structural shape.
• Plant beneath lightly canopied trees with ferns and other acid-soil woodland plants.
• Grow in large, well-drained containers filled with ericaceous compost where garden soil is alkaline.

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

Plant it with: Japanese pieris, Azaleas, Camellias, Japanese forest grass, Hostas and Japanese painted fern.

Wildlife: Flowers attract small bees and other insects. Female plants can carry black berries when a compatible male Japanese holly flowers nearby; birds may eat the berries, and dense foliage offers shelter.

• Yellow leaves with greener veins often indicate alkaline soil: test pH and use a suitable acidic bed or an ericaceous container rather than repeatedly adding iron.
• Root rot causes wilting and dieback in wet soil: improve drainage, reduce watering and remove badly affected plants.
• Spider mites cause fine stippling and bronzing, especially in hot, dry conditions: rinse leaf undersides and use a labelled horticultural soap if needed.
• Winter scorch browns exposed foliage: shelter from cold winds, mulch the roots and water during dry autumn weather before freezing.

Treat the leaves and especially the berries as toxic to people, cats, dogs and horses if eaten. Ingestion can cause vomiting, diarrhoea and abdominal discomfort; poisoning is usually gastrointestinal rather than life-threatening, but seek medical or veterinary advice after ingestion.

Where it spreads. Japanese holly has escaped cultivation in parts of the eastern United States, including Virginia. Check local invasive-plant guidance before planting near natural woodland; seed-grown offspring will not necessarily remain compact.

• Common box (Buxus sempervirens)

  Box has opposite pairs of leaves, usually with smooth edges; Japanese holly has alternate leaves with fine scalloping.

• Inkberry (Ilex glabra)

  Inkberry usually has longer leaves with teeth mainly near their tips and often spreads by suckers; Japanese holly has smaller leaves scalloped along more of the edge.

• Convex-leaved Japanese holly (Ilex crenata 'Convexa')

  Its leaves are noticeably rounded and cupped or bulging. 'Compacta' has flatter leaves; closely clipped plants can be difficult to distinguish without a reliable label.

Crenata refers to the scalloped leaf margins, while 'Compacta' describes the cultivar's dense growth.

Propagation. Take semi-ripe cuttings in summer and root them in a moist, free-draining medium under humid conditions. Seed does not reliably reproduce the cultivar.

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.