If insecticides are going to be used, spray when crawlers are observed. Repeat treatments in 10 days. Read and follow all label instructions and precautions. A number of factors other than insects or diseases can contribute to the decline of dogwoods in the landscape, especially mower injury, overfertilization and poor growing conditions. Leaf scorch is caused by environmental conditions that are too dry.
Leaves have dry and browning edges.
On severely stressed trees, drying and browning of the areas between the veins and leaf drop can occur. This condition looks just like a disease, but it isn t. Dogwoods have a very shallow root system, and thus are very susceptible to drought stress, especially newly planted trees in full sun. After transplanting, be sure to water as needed during the first summer and fall to avoid leaf scorch. Do not grow grass over the root system area. Control of disease and insects on large trees is usually not feasible, since adequate coverage of the foliage with a pesticide cannot be achieved.