Ilex crenata, Japanese holly
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Broadleaf Evergreen Shrubs

Ilex crenata

Japanese holly

Aquifoliaceae

Eastern Asia including Japan, Korea, eastern China, and Taiwan

At a Glance

TypeShrub
HabitMounding
FoliageEvergreen
Height3-10 feet (0.9-3 m)
Width3-8 feet (0.9-2.4 m)
Maturity10 years

Growing Zones

USDA Hardiness Zones

5 - 8
Zone 5
Zone 6
Zone 7
Zone 8
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Attracts Pollinators
Deer Resistant
Container Friendly
Maintenancemoderate

Overview

A broadleaf evergreen shrub reaching 3-10 feet (0.9-3 m) tall and 3-8 feet (0.9-2.4 m) wide at maturity, depending on cultivar and pruning. Growth rate is slow to moderate, adding 4-8 inches (10-20 cm) per year. Leaves are small, ovate to elliptical, 0.5-1.25 inches (1.3-3 cm) long and 0.25-0.5 inches (6-13 mm) wide, with crenate (rounded-toothed) margins and no spines. Foliage is glossy dark green, fine-textured, and densely arranged on the stems, giving the plant a boxwood-like appearance. Leaves are alternately arranged, which distinguishes it from true boxwood (Buxus), where leaves are opposite. Dioecious: male and female flowers on separate plants. Small white flowers appear in June at leaf axils, each approximately 0.2 inches (5 mm) across; individually inconspicuous. Female plants produce glossy black drupes approximately 0.25 inches (6 mm) in diameter, ripening in fall. Bark is smooth and gray-green on young stems. The species has a naturally rounded to spreading habit, though numerous cultivars offer upright, columnar, or compact forms. Hardy to approximately -10°F (-23°C), though foliage may bronze or desiccate in exposed positions during severe cold. Susceptible to black root rot (Thielaviopsis basicola) in poorly drained soils, and to spider mites in hot, dry conditions.

Native Range

Native to eastern Asia, including Japan, Korea, eastern China, and Taiwan. Found in montane forests, forest edges, and scrubland at elevations of 1,000-5,000 feet (300-1,500 m), typically as an understory shrub in mixed deciduous-evergreen woodlands on acidic to neutral soils.

Suggested Uses

Commonly used as a boxwood substitute for formal hedging, edging, and foundation plantings at 2-3 foot (60-90 cm) spacing. Frequently used in Japanese-style gardens, formal parterres, and as topiary specimens. Suitable for container culture in pots of at least 5 gallons (19 L). Tolerates urban pollution. Compact and dwarf cultivars are used for low edging and ground cover applications.

How to Identify

Distinguished from other hollies by the absence of spines and the small leaf size: leaves are 0.5-1.25 inches (1.3-3 cm) long with crenate (rounded-toothed) margins. Closely resembles boxwood (Buxus) in texture and form, but can be differentiated by alternate leaf arrangement (boxwood has opposite leaves), glossy black berries on female plants (vs. no fleshy fruit on boxwood), and a slightly more open branching pattern. Foliage lacks the pungent scent characteristic of boxwood when crushed.

Appearance

Size & Dimensions

Height3' - 10'
Width/Spread3' - 8'

Reaches mature size in approximately 10 years

Colors

Flower Colors

white

Foliage Colors

dark green

Bloom Information

Bloom Period

~2 weeks
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Summer
Small white flowers appear in June in axillary clusters on the previous year's growth. Individual flowers are approximately 0.2 inches (5 mm) across, four-petaled, and individually inconspicuous. Bloom lasts approximately 2 weeks. Female plants produce glossy black drupes approximately 0.25 inches (6 mm) in diameter by September to October when a male pollinator is nearby. Flowers are visited by small bees and flies.

Detailed Descriptions

Flower Description

White

Foliage Description

Glossy dark green

Growing Conditions

Sun Requirements

Full Sun
Partial Shade
Requires 3-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.0 - 6.5(Acidic)
357912
Soil Types
loamsand
Drainage
well drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

5-10 years

Care & Maintenance

Care Guide

Plant in well-drained, slightly acidic soil with a pH of 5.0-6.5; alkaline soils cause chlorosis. Water regularly during the first two growing seasons; established plants tolerate brief dry periods but perform better with consistent moisture, particularly in summer. Mulch root zone with 2-3 inches (5-8 cm) of acidic organic material such as pine needles or composted bark. Black root rot (Thielaviopsis basicola) is the most serious disease, causing stunted growth and foliar yellowing in poorly drained or compacted soils; there is no chemical cure, and affected plants should be removed. Spider mites cause stippled, bronzed foliage in hot, dry conditions; check leaf undersides and treat with miticide or strong water spray. Nematodes can damage roots in sandy soils in warmer zones. Protect from cold, desiccating winter winds in zones 5-6, as foliage may bronze or scorch.

Pruning

Responds well to shearing and is commonly maintained as formal hedging, edging, or topiary. Prune or shear in late spring to early summer after the flush of new growth has hardened. A second light shearing in mid-summer maintains a tight formal shape. Avoid pruning after August, as late-season growth is susceptible to winter cold damage. Tolerates hard rejuvenation pruning to 6-12 inches (15-30 cm) in late winter; regrowth is slow, taking 2-3 years to fill in fully.

Pruning Schedule

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late springsummer

Maintenance Level

moderate

Container Growing

✓ Suitable for container growing

Minimum container size: 5 gallons

⚠️ Toxicity Warning

Toxic to pets and humans