Winterberry Ilex opaca

American holly is an evergreen tree in the Aquifoliaceae (holly) family that grows slowly from 40 to 60 feet tall in an open conical to pyramidal shape.  In nature, it is found growing as an understory tree or shrub in moist deciduous forests in the central and southeastern USA. The genus name Ilex is in reference to the similarity of the evergreen leaves to Quercus ilex or holm oak.  The specific epithet opaca means dull, dark or opaque in reference to the dullness of the leaf surface.

The tree has alternate leaves with spiny toothed and sometimes smooth margins. The bark is gray-white in color and may be splotched or warty with striking red or brown lichens growing on it. Small, dull green-white, solitary flowers mature in late spring. Female specimens that are pollinated by a male plant produce a bright red or orange fruit which matures in the fall and persists into the winter. American holly has generated numerous cultivars, some of which are listed in this entry.

American holly is easily grown in average, consistently moist, acidic, well-drained soils in full sun to part shade. . It will tolerate a broad range of soil conditions and is salt spray, wind, and pollution tolerant, but will not tolerate flooding or soils saturated with moisture. For optimum growth avoid poorly drained soils. Its best growth in the wild usually occurs in rich bottomlands and swamp margins. It will not do well in locations not protected from cold winter winds and winter sun. Part afternoon shade is best in hot summer climates. Being situated in too much shade will cause the plant foliage to lose density.

Uses for this large shrub that may have limbs all the way to the ground include privacy screens and hedges.  Pruned as a tree it can be a specimen planting. It doesn’t make a good plant for small yards, but can be a beautiful plant when given space to grow.  The evergreen leaves and fruits on female plants make for beautiful color and interest in a winter garden.  Branches from this species are often used in the creation of Christmas wreaths.  

Fire Risk: This plant has a high flammability rating and should not be planted within the defensible space of your home. Select plants with a low flammability rating for the sites nearest your home. 

Quick ID Hints:

• Dull, dark green leaves are both entire and spiny.
• Spines are evenly spaced and are long and sharp.
• Leaves usually have a dull, dirty look.

Insects, Diseases, and Other Plant Problems: The leaves are typically yellow in alkaline soils and have a dusty, dirty look to them

VIDEO: Part of the Native Plant Picks series from the North Carolina Sea Grant led Coastal Landscapes Initiative.

Additional video Ilex opaca created by Andy Pulte for “Landscape Plant Identification, Taxonomy and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.