Woody trees and shrubs may exhibit decline resulting from the stresses that can occur during their lives. Stress may be the result of improper plant or site selection, incorrect planting or maintenance practices, or poor soil conditions. Injury from equipment, weather, or chemicals can also lead to stress and decline. In addition, biological stresses such as diseases, insects, and wildlife could result in stress and decline of woody ornamentals. Symptoms of stress and decline include dieback (Figure 1), leaf scorch, stunting, premature fall color or leaf drop, production of water sprouts or suckers (Figure 2), and signs of disease or insects.
Typically, one or more primary stresses cause deterioration of plant health, followed by secondary pathogens and/or insects that further decline or destroy plants. Determining causes of decline requires careful examination of plants and growing sites, as well as knowledge of site history. Nevertheless, diagnoses may be difficult, as the original cause(s) of plant stress may be obscure or no longer present.
For more information on stress and decline in woody plants and related disease problems, review the publication Stress and Decline in Woody Plants (ID-50).
By Kimberly Leonberger, Plant Pathology Extension Associate, and Nicole Gauthier, Plant Pathology Extension Specialist