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. Prune in winter if needed. Plants of this species are dioecious (separate male and female plants). Female plants need a male pollinator in the area in order to bear fruit. This species can be difficult to grow in the St. Louis area because it dislikes cold winters (not considered winter hardy in USDA Zone 5 and the northern part of USDA Zone 6) and also dislikes hot and humid summers. It grows much better in the climate of the Pacific Northwest where it has naturalized.
Noteworthy Characteristics
Ilex aquifolium, commonly called English holly, is native to Europe, western Asia and north Africa. It is an erect, pyramidal, densely-branched, evergreen tree that typically grows to 30-50’ (less frequently to 80’) tall. It also may be trained and grown as a large shrub (10-15’ tall). Elliptic, leathery, glossy, wavy-margined, evergreen, dark green leaves (1-3” long) have large spiny teeth. Greenish-white flowers appear in May. Flowers are fragrant but generally inconspicuous. Pollinated flowers give way to berry-like red (less frequently orange or yellow) drupes (1/4” 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).
Specific epithet comes from the Latin word acus meaning needle and folium meaning leaf in reference to the spiny leaves.
'Aurea Marginata' is a cultivar that features spiny glossy green leaves with distinctive showy yellow leaf margins. As is the case with the straight species, this variegated cultivar can be grown as a tree or a shrub. As a tree, it is not likely to exceed 40' over time. Cultivar name refers to the leaf variegation (aurea meaning gold and marginata meaning margins).
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
By reputation, English holly is a better ornamental tree than American holly (see I. opaca), but it has less winter hardiness and is more difficult to grow in the lower Midwest and deep South. Effective as a specimen or in small groups. Foundation plantings. Foliage and fruit provide good color for the winter landscape. Tall hedge.