Turf Grass Diseases: Identification, Prevention & Treatment Guide

A lush, green turf lawn is a point of pride—but fungal diseases like brown patch, dollar spot, and anthracnose can quickly turn it brown and patchy. Understanding these common pathogens and implementing integrated management keeps your turf healthy year-round.

Foundations of Disease Prevention

Proper maintenance is your first defense: appropriate watering, aeration, fertilization, and mowing. Most outbreaks occur during extreme stress—drought, excessive moisture, or temperature extremes. Pathogens often lie dormant until conditions favor them.

Brown Patch (Rhizoctonia solani)

Identification

Circular brown patches appear in summer heat and humidity, especially in high-nitrogen lawns. Patches often show a darker "smoke ring" at the edge and can exceed a foot in diameter. Grass within thins or dies completely.

Control

• Remove morning dew (drag a hose or use a dew whip)
• Reduce nitrogen fertilization
• Apply fungicide at first sign

Anthracnose: Foliar Blight & Basal Rot (Colletotrichum graminicola)

Identification

Irregular yellow/brown patches in extreme temperatures. Magnification reveals fungal fruiting bodies on leaves and stems. Early signs: yellow-red lesions on older leaves, progressing to younger tissue.

Control

• Cultural: proper irrigation, fertilization, soil health
• Fungicidal sprays for active infections
• Early detection is critical

Dollar Spot (Sclerotinia homoeocarpa)

Identification

Small (2–3 inch), straw-colored circular spots with brown margins, often merging into larger patches. Most visible after mowing. Favored by high humidity and low soil nitrogen.

Control

• Cultural: maintain optimal nitrogen, remove dew, avoid moisture stress
• Light nitrogen application if deficient during outbreak
• Targeted fungicide application

Integrated Management Is Key

No single tactic works alone. Combine cultural practices—correct mowing height, deep infrequent watering, balanced fertility, aeration—with timely fungicide use when thresholds are reached. Regular monitoring catches problems early, when they're most treatable.