Powdery Mildew is most often found in shaded, moist areas that suffer from poor air circulation. Most often it is found near the shade of the house or a tree during August –October. Grasses under stress are particularly susceptible to this disease. Powdery mildew first appears as a powdery white growth confined to the upper surface of the grass blade. The fungus grows rapidly and soon covers the leaves of the entire plant. If the disease progresses, its suffocating activity continues to point where the blades yellow and plants die.
In general, powdery mildew is not considered to be a serious problem and is usually more of a nuisance. Plants are seldom killed, but they become more likely to suffer from other diseases and stresses. Kentucky blue grasses are the most susceptible.
Control: Improve air circulation and reduce shade by pruning nearby trees and shrubs. Prune during the growing season to be able to tell which branch to remove for best light advantage. Regular fertilization is important but over-fertilization leads to too much succulence and increased susceptibility.
In addition, our recommendations would include aerating to keep the lawn healthy. Winter fertilization is one way to round out the lawn's nutritional needs.