Most of us enjoy the spring blooming of the white to pink flowers of dogwood trees. Sadly, many dogwoods are susceptible to a fungal disease called powdery mildew. It can cover the leaves and infect young buds, shoots, and flowers, dwarfing developing leaves and blooms, and causing distortion and even death. Because it survives on the surface of dogwood trees, it is not difficult to eliminate with a combination of cultural modifications and fungicides.
To control powdery mildew don’t apply very high nitrogen to the dogwood during blooming time. Prune out dead limbs that might be harboring the fungi, but don’t prune excessively as this can stimulate new growth. Eliminate brush or plant material surrounding the dogwood that may interfere with air circulation.
Irrigate early in the morning to reduce humidity immediately around the dogwood. Mulch the tree with a thin layer of mulch less than two inches thick. Water at the base of the tree, making sure not to get water on the dogwood leaves. Watering onto the leaves can cause other mildews or leaf scorch.
Treat dogwoods with a fungicide or a summer horticultural oil at temperatures below 90 degrees. We at Virginia Green Lawn Care prefer the fungicide treatment due to the possible burning from horticultural oil when temperatures approach 90 degrees. A coating of the leaves provides an effective treatment for powdery mildew.
When planting dogwoods select resistant varieties or apply a fungicide to control powdery mildew. Call us here at Virginia Green Lawn Care and get a free Premium Tree and Shrub estimate and allow us to help you protect your dogwood trees.