Common Name: holly
Type: Broadleaf evergreen
Family: Aquifoliaceae
Zone: 6 to 9
Height: 15.00 to 25.00 feet
Spread: 10.00 to 15.00 feet
Bloom Time: May
Bloom Description: Greenish-white
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Suggested Use: Hedge
Flower: Fragrant, Insignificant
Leaf: Evergreen
Attracts: Birds
Fruit: Showy
Other: Winter Interest
Tolerate: Clay Soil
Culture
Grow in average, medium moisture, well-drained soils in full sun to part shade. Best in locations protected from cold winter winds. Part afternoon shade is best in hot summer climates. Avoid poorly drained soils. Tolerates hot summer temperatures better than its I. aquifolium parent. Prune in winter if needed. This hybrid holly is dioecious (separate male and female plants). Female plants need a male pollinator in order to bear fruit. Winter hardy to USDA Zone 6B. Should be sited in a protected location if grown in the St. Louis area (Zone 6A).
‘Loch Raven’ is a male cultivar.
Noteworthy Characteristics
Ilex × koehneana, commonly called Koehne holly, is a cross between I. aquifolium and I. latifolia. It is an erect, narrow-pyramidal, densely-branched, large, hybrid evergreen shrub or small tree that typically grows to 15-25’ tall with a spread to 10-15’ wide. Branches are clad with glossy, spiny-margined, elliptic, evergreen, dark green leaves (2-3” long). Inconspicuous, tiny, greenish-white flowers bloom in May. Flowers are fragrant but generally inconspicuous. Pollinated flowers give way to berry-like red drupes (1/3” diameter) which ripen in fall and persist into winter. Birds are attracted to the fruit.
Genus name comes from the Latin name Quercus ilex for holm oak in reference to the foliage similarities (holm oak and many of the shrubs in the genus Ilex have evergreen leaves).
The hybrid name koehneana honors Bernard Koehne (1848-1918), German botany professor.
‘Loch Raven' is a male cultivar with dark olive green leaves. Leaves are moderately spiny.
Problems
Potential insect problems include holly leaf miner, spider mites, whitefly and scale. Potential disease problems include leaf spot, leaf rot, tar spot and powdery mildew. Plants are also susceptible to leaf drop, leaf scorch and chlorosis (yellowing of leaves in high pH soils).
Uses
Effective as a specimen or in small groups. Foundation plantings. Screen. Tall hedge.