Grey Leaf Spot Fungus Lawn Disease
Grey leaf spot is caused by the fungus, Pyricularia grisea, and causes severe damage primarily on St. Augustinegrass. Tall fescue may also be damaged by gray leaf spot. Leaf spots on grass blades are tan to gray with purple to brown margins. When the disease is severe, the entire planting may appear a brownish color or scorched, similar to damage caused by drought. This disease most commonly occurs during warm, rainy periods in the summer.
Prevention and Treatment
Plant resistant cultivars. Avoid excessive applications of nitrogen, especially during warm, humid weather. Irrigate deeply only when needed and in the early morning. Avoid stresses induced by drought, or compacted soil. Improve air movement and light intensity by pruning trees and undergrowth. Fungicide may be necessary for control. Your Fairway Lawns technician can determine if a fungicide treatment plan is necessary.