Introduction

Dwarf Japanese holly, (Ilex crenata) is one of the finest-textured shrubs available (Figure 1). These durable hollies are very flexible as landscape plants as they grow well in full sun to light shade. They lend themselves to a variety of soil types and are available at most nurseries and garden centers. The dark green foliage lends a rich air to any landscape, particularly when combined with lighter green turf and shrubs. Plant on 3- to 4-foot-centers to establish a row or mass planting.

General Information

Scientific name: Ilex crenata 'Helleri'

Pronunciation: EYE-lecks kren-NAY-tuh

Common name(s): 'Helleri' holly

Family: Aquifoliaceae

Plant type: shrub

USDA hardiness zones: 5B through 8A (Figure 2)

Planting month for zone 7: year round

Planting month for zone 8: year round

Origin: not native to North America

Uses: foundation; mass planting; container or above-ground planter; superior hedge; border

Availablity: generally available in many areas within its hardiness range

Description

Height: 3 to 6 feet

Spread: 5 to 8 feet

Plant habit: round

Plant density: dense

Growth rate: slow

Texture: fine

Foliage

Leaf arrangement: alternate

Leaf type: simple

Leaf margin: serrulate

Leaf shape: obovate

Leaf venation: pinnate

Leaf type and persistence: evergreen

Leaf blade length: less than 2 inches

Leaf color: green

Fall color: no fall color change

Fall characteristic: not showy

Flower

Flower color: white

Flower characteristic: spring flowering

Fruit

Fruit shape: round

Fruit length: less than .5 inch

Fruit cover: fleshy

Fruit color: unknown

Fruit characteristic: rarely fruits

Trunk and Branches

Trunk/bark/branches: not particularly showy; typically multi-trunked or clumping stems

Current year stem/twig color: green

Current year stem/twig thickness: thin

Culture

Light requirement: plant grows in part shade/part sun

Soil tolerances: slightly alkaline; clay; sand; acidic; loam

Drought tolerance: high

Soil salt tolerances: unknown

Plant spacing: 36 to 60 inches

Other

Roots: usually not a problem

Winter interest: no special winter interest

Outstanding plant: not particularly outstanding

Invasive potential: not known to be invasive

Pest resistance: long-term health usually not affected by pests

Use and Management

The dwarf Japanese hollies are best used in mass groups as low shrubs, low hedges, or tall groundcovers. The compact habit of growth, slow growth rate, and small leaves make these ideal plants for use as clipped, formal hedges. Adjacent plants will often grow together looking like a row or group of green mounds. Eventually, the crowns grow completely together forming a sea of green.

Cultivars: 'Convexa' grows to about eight feet in a vase or rounded form and has cupped, glossy leaves; 'Compacta' has a compact growth habit and grows to about five feet tall; 'Helleri' has a slight grayish cast to the foliage which sets it apart from other Japanese hollies; 'Northern Beauty'—improved cold tolerance, reaches a height and spread of three feet; 'Rotundifolia'—dense habit, large size, to 12 feet.

Propagation is by cuttings.

Pests and Diseases

Pest problems are many, including scale, spider mites, spittle bugs, and nematodes, but these are often of minor consequence.

No diseases are of major concern.