The dogwood is a favorite of homeowners and landscapers; and nothing can worry a homeowner like the threat of a disease to their prized dogwood. Dogwood trees can have several problems such as brown, distorted leaves and severe leaf drop. Fortunately, these problems are rarely life-threatening. Here are some of the common diseases encountered with dogwoods in Georgia:
- POWDERY MILDEW: Look for a dusty covering on all or part of the leaves. The affected leaf areas eventually die. Some leaves will be distorted. This can contribute to the scorched appearance of the foliage. Symptoms of either powdery mildew or water stress usually involve most or all of the foliage on the tree. To treat, protect new foliage by spraying a labeled fungicide throughout the summer. The powdery mildew fungus overwinters on twigs and trunks so spray again at bud break next spring. Remove all leaves under the tree this fall.
- DOGWOOD ANTHRACNOSE occurs in early spring. Leaves will have lots of pinhole sized spots. The spots can be numerous and cause the blooms to look dirty. The blighted leaves are not shed in the fall; they stay on the tree through the winter. Years after these first symptoms, cankers can form on the scaffold branches and main trunk. In severely diseased trees numerous water sprouts (epicormic shoots) develop in early spring. Over a period of 3 to 4 years these cankers can eventually kill the tree. To treat, protect new foliage in wet spring weather by spraying a labeled fungicide, from bud break until leaves are fully opened. Stop when summer begins.
- DOGWOOD BLIGHT causes dead spots that enlarge to kill most of the leaf. It starts on the lower branches and works upward. Although the disease has been identified in a few spots in Atlanta, it is very unlikely that it could be widely distributed. To treat, protect new foliage by spraying with a labeled fungicide, from bud break until beginning of summer. Remove all leaves from under trees this fall.