The broadleaf evergreen English holly tree (Ilex aquifolium) grows widely across Europe, parts of Asia and areas of the United States. The foliage appears a dark, glossy green or variegated. Each leaf possesses unique spines along its edges. English holly is widely grown commercially for holiday decorations and floral arrangements. The tree thrives in zones 6 to 8. Numerous cultivators are available.
The English holly tree easily attains a height of 40 to 50 feet. Its width averages 15 feet. Leaves measure up to 3 inches in length. Grown either as a single trunk tree or a multi-trunked shrub, the tree is widely favored in hedge plantings. Easily invasive, it spreads rapidly in a forest setting, producing large thickets that often choke out native plant growth. The tree easily propagates by sending out suckers.
English holly trees grow well in either full sunlight or partial shade. The tree does require moist soil and does not endure drought well. In its quest for ample water, the aggressive tree will easily seek out all water from the soil and often cause the demise of neighboring plants, shrubs or trees if ample water is not provided to the planting location.
Tiny white flowers appear on the English holly tree each spring. The flowers are highly favored for their pleasant sweet scent. The flowers are pollinated by bees. Both a male and female holly tree are required for pollination to occur and berry production to begin. Females must be planted within 100 feet of a male to ensure berry production.
Berry production takes place only on the female trees and appear in colors of red, orange, white, yellow or black. Berries begin appearing in the fall and into the winter months. The berries are toxic to humans, but birds enjoy consuming them. Most seeds are spread by birds eating the berries and then defecating the seeds in a new location.
Aphid colonies often attack new shoots of the holly tree by attaching themselves to the plants stems to suck the sap. Control is easily attained by simply hosing the aphids off using a garden hose.