Dogwoods, ornamental , species of pear, maples, oaks, and other popular urban landscape trees have been especially susceptible to this summer's hot, dry weather. These symptoms are signals the plant isn't receiving an adequate amount of moisture. Scorch appears along leaf edges and occurs when water is lost from leaves more rapidly than it can be replaced from the soil. As a result of moisture stress, the leaves become dry and scorched. Scorch is more likely to occur when hot, dry winds accompany drought periods.
Defoliation sometimes accompanies drought stress.
Shallow-rooted trees are especially sensitive to hot, dry weather. For example, dogwoods in home landscapes, and in woodland settings, typically show severe marginal leaf scorch and foliar wilt. Frequently, drought-affected dogwoods have upper branches with light to deep red leaves. Young trees transplanted within the past few years are also vulnerable to environmental stress and should be watered the equivalent of a one inch rain per week. As a general rule, water each week it does not rain.