Ornamental and Tree Diseases

It's a fact -- money does grow on trees and other plants in the home landscape. Healthy trees and woody ornamentals add to property value (an average 15 percent, according to recent research), plus an attractive and well-maintained landscape beautifies the neighborhood and provides a great place to relax.

One of the most important components of a home landscape program is protection of trees and shrubbery from disease pests. Unfortunately, landscape plants are vulnerable to attack by a wide range of diseases caused primarily by fungi, bacteria, viruses, and nematodes, which are referred to as biotic agents of plant disease.

Most disease-causing agents are microscopic, which means that homeowners won't see the microorganisms which cause blights, leaf spots, and other problems on their azaleas, roses, hollies, oaks, maples, and other plants which are popular in southern landscapes. Although these pests are small in size, the damage they cause is often quite visible, and detracts from the beauty of the home landscape. In some cases, when susceptible plants are planted, or conditions are favorable for disease development, plants are killed by diseases.

In addition to the biotic agents of disease, trees and woody ornamentals are also frequently affected by non-parasite disorders (abiotic agents of disease), such as injuries caused to trees during home and driveway construction, compaction of soil around roots, or poor growing conditions brought on by extended periods of drought or too wet or cold weather.

As an additional example, plants such as azaleas, camellias, photinia, hollies, and other popular woody ornamentals are susceptible to root rot under conditions of poor drainage in landscape beds. Prolonged exposure of roots to saturated soils leads to plant death and the expense of plant replacement.

Although landscape plants are vulnerable to biotic and abiotic agents of disease, this doesn't mean a healthy landscape isn't possible. Most plant health problems can be prevented, provided home landscapers become more knowledgeable of diseases, and recognize that problems can be prevented provided precautionary steps are taken to prevent parasitic and non-parasitic disease development.