Ilex

Holly is a genus of 564 species and numerous cultivars of perennial shrubs and trees in the holly family (Aquifoliaceae). Hollies are found in temperate and tropical forests on every continent (except Antarctica). As many as 14 species are native to North Carolina. The genus name, Ilex, comes from ilex, the common name for the holm oak (Quercus ilex), presumably because both have tough, evergreen leaves.

Hollies thrive in full sun to partial shade in acidic, well-drained soil, although they tolerate a wide range of soil types, from moist to dry, including clay. Hollies tolerate drought, shade, air pollution, poor soils, and are easy to transplant. Most of the deciduous species and hybrids will not thrive in areas with high heat and humidity (USDA zones 8 and 9). The tropical species are not frost hardy. 

Hollies are dioecious, meaning that only one sex is found on any one plant, thus both male and female plants must be grown if fruits are desired. Holly flowers are pollinated by bees and some make excellent honey plants.

There are many species and cultivars of holly available in the trade. Larger species are suitable for specimens, accents, specimens and screens. The spiny species are useful as security barriers. Smaller species and cultivars are suitable for hedges and borders, accents, and even ground cover. Use hollies in Asian, children’s, English, cottage, or winter gardens. The native species are ideal for native gardens, where birds can feast on the fruit.

Insects, Diseases, and Other Plant Problems: Spider mites and nematodes are occasional pests.  Alkaline soils will cause the leaves to yellow.

The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common diseases and insect pests.