Leaf Spot on Turfgrasses
The many strains of leaf spot are probably the hardest disease for homeowners to distinguish and diagnose.
Most turfgrasses can get some type of leaf spot. The best way to determine what strain of the disease is present is to recall what the weather patterns in the two weeks prior to the problem emerging.
Each type of leaf spot needs certain environmental conditions for growth and development. Some leaf spot strains favor cooler, wet weather patterns while other strains prefer warm and moist conditions. Most leaf spots emerge during the summer months. Signs include turf beginning to thin out, brownish lesions developing on the blades of the turf grass plants, or water soaked lesions on the blades.
Proper cultural practices play an important role in reducing the chance for infections. Irrigate in the morning when needed and do so infrequently, yet deeply. Do not fertilize cool season grasses during the summer months, because this will promote lush growth which is more susceptible to infection.
Mow at the recommended heights. Dethatch the lawn if the thatch layer is over half an inch. Use appropriate turf grasses for areas that have special needs or requirements.
Fungicides can be used with great success when the disease is detected early. Several applications maybe required to keep leaf spot in check. Call your local extension office for the most recent list of registered products.
Also see: Horticulture Publications