To Health of Dogwoods Powdery mildew on dogwoods has increased in South Carolina in recent years on both open-grown and partly shaded trees. Most landscape trees that are affected by powdery mildew get the disease late in the summer, but dogwoods become infected early and the results can be devastating. Infected leaves can show not only the white powdery fungus on leaf surfaces, but also scorched margins, dead patches, reddish discoloration and yellowing.
Trees can defoliate prematurely.
Homeowners often want to know if fungicides can be used to help manage this disease. The answer is yes, but cultural practices that enhance the health of the tree is the first line of defense. Select healthy plants from a reputable nursery and plant them correctly. Clemson recommends mulching to prevent unnecessary trunk and branch injuries from lawn mowers and string trimmers. Irrigate during dry periods, prune out dead and rubbing branches and prune back overhanging branches from nearby trees to allow better sunlight penetration and air movements.