Ilex cornuta 'Carissa': Carissa Holly

Introduction

Carissa holly is a compact, dense evergreen shrub with small, glossy, dark green leaves, each with a single terminal spine. The somewhat-showy clusters of fragrant, springtime, white flowers are followed in fall and winter by bright red berries. However, the berry display is mostly inferior to Ilex cornuta 'Burfordii'. The shrub stays small, eventually growing to about 8 feet. Most carissa holly plants are kept smaller than this. The plant occasionally reverts back to a 'Rotunda' holly leaf form, a plant to which it is closely related. 'Rotunda' has many spines along the margins of the leaf.

General Information

Scientific name: Ilex cornuta 'Carissa'

Pronunciation: EYE-lecks kor-NOO-tuh

Common name(s): carissa holly

Family: Aquifoliaceae

Plant type: shrub

USDA hardiness zones: 8 through 10 (Figure 3)

Planting month for zone 8: year-round

Planting month for zone 9: year-round

Planting month for zone 10 and 11: year-round

Origin: not native to North America

Invasive potential: not known to be invasive

Uses: border; mass planting; cut foliage/twigs; superior hedge

Availability: generally available in many areas within its hardiness range

Description

Height: 3 to 4 feet

Spread: 4 to 6 feet

Plant habit: round

Plant density: dense

Growth rate: slow

Texture: medium

Foliage

Leaf arrangement: alternate

Leaf type: simple

Leaf margin: terminal spine

Leaf shape: ovate

Leaf venation: pinnate

Leaf type and persistence: evergreen

Leaf blade length: 2 to 4 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 0.5 inch

Fruit cover: fleshy

Fruit color: red

Fruit characteristic: rarely fruits

Trunk and Branches

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

Current year stem/twig color: green

Current year stem/twig thickness: medium

Culture

Light requirement: plant grows in part shade/part sun

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

Drought tolerance: high

Soil salt tolerances: poor

Plant spacing: 36 to 60 inches

Other

Roots: usually not a problem

Winter interest: no special winter interest

Outstanding plant: not particularly outstanding

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

Use and Management

A dense, rounded silhouette develops without clipping making it well suited for planting along a foundation. Plant 3 to 4 feet apart to form a hedge, farther apart in a shrub border. It is often used as a mass planting on commercial properties to form a tall ground cover or low shrub mass around parking lots. One yearly pruning can easily keep this plant in bounds in most landscape settings, unless it is clipped into a formal hedge. Two or three clippings may be needed for hedges. It shears fairly well, but will thin slightly toward the base, especially if not located in full sun. Clip the hedge so it is wider at the bottom than at the top to allow maximum light penetration to bottom foliage. This will help keep the hedge full to the ground.

Growing best in rich, well-drained, slightly acid soil, carissa holly does well in full sun or part shade. The plant is very drought tolerant, requiring little, if any, irrigation once established in the landscape. One or two fertilizations are all that is needed to maintain good leaf color and adequate growth.

Propagation is by cuttings only.

Pests and Diseases

Holly can be bothered by scale insects and aphids.

No diseases are of major concern.