Lawn diseases can turn a lush yard into a patchy mess seemingly overnight. Learn to identify common fungal diseases early, understand what conditions cause them, and apply the right treatments to restore your lawn.
Round or irregular brown areas that expand outward. Often worst in hot, humid weather.
Silver-dollar-sized straw-colored spots, often with a reddish-brown border.
Orange, yellow, or powdery coatings on individual grass blades rather than dead patches.
Rhizoctonia solani
Circular brown patches ranging from a few inches to several feet. Most active in hot, humid weather with nighttime temps above 65°F.
Clarireedia jacksonii
Small, silver-dollar-sized bleached spots that can merge into larger areas. Thrives in low-nitrogen lawns with heavy dew.
Puccinia spp.
Orange-yellow powder on grass blades that rubs off on shoes and mowers. Common in slow-growing, under-fertilized lawns.
Most lawn diseases are caused by fungi that thrive when conditions are right. Prevention is far easier than treatment.
Watering early allows grass to dry during the day. Wet grass overnight creates ideal conditions for fungal growth.
Excess nitrogen, especially in summer, makes lawns more susceptible to diseases like brown patch. Follow recommended rates.
Trim overhanging branches and thin dense plantings near the lawn to reduce humidity at grass level.
Mowing too short weakens grass and invites disease. Never remove more than one-third of the blade at a time.
Core aeration reduces thatch buildup and improves drainage—both key factors in preventing fungal diseases.
When overseeding or establishing a new lawn, select grass cultivars with built-in disease resistance for your region.