Holly bushes (Ilex spp.) are common landscape plants that are easy to care for. Numerous varieties are available with different leaf shapes and colors, as well as growth habits and sizes. Holly bushes may be evergreen or deciduous. Some bear red, yellow or black berries that attract birds.
Holly bushes grow in sun or partial shade, in almost any type of soil. They need regular irrigation but will not tolerate soggy conditions. Most holly bushes are not bothered by pests or diseases.
Leaf spots caused by a fungal disease affect holly bushes in the winter or spring. The old foliage may drop heavily before the new spring growth appears, but leaf spots do not cause permanent damage to the plants.
Phytophthora, a soil-borne fungus, causes root rot on holly bushes in areas with poor drainage. The roots turn dark brown to black, and the plant develops stunted growth and chlorosis of the leaves. Infected plants will decline over several seasons and finally die.
Nematodes are microscopic roundworms that feed on the roots of plants, including holly bushes. The roots develop abnormal growths, such as galls and swellings that result in poor growth. Symptoms include yellow or bronze leaves, loss of foliage and stem dieback. Infected plants do not respond to fertilization, slowly decline over several years and eventually die.
Holly bushes can often withstand severe infestations of pests without any damage. Japanese wax scale insects, small white waxy blobs on limbs and twigs, are one of the most common pests on holly bushes. Cottony masses of tea scale insects live on the lower leaf surfaces of holly bushes. Neither pest causes any serious damage.
Southern red mites attack the lower leaf surfaces of holly bushes in the spring or the fall. They cause small chlorotic spots on the leaves, and a heavy infestation can cause the foliage to appear bronzed.
Native holly leafminers form tunnels on the upper leaf surfaces of holly bushes. The tunnels look like elongated, irregular yellow or brown splotches and do not cause any permanent damage.
Chlorosis, or yellowing, of the foliage of holly bushes can be caused by soil with a high pH or not enough nitrogen. Foliage, especially of young holly bushes, can be damaged by windy or dry conditions.
Little or no fruit can be caused by a variety of conditions--young immature plants, flowers damaged by frost, poor pollination or no male plant available for pollination.