Brown Spots in Tall Fescue: Detective Work Before Treatment

Year-old tall fescue has brown spots despite regular mowing (every 4 days) and watering (1 hr, 2x/week). Raking pulls dead grass. How to fix?

Step 1: Soap Flush for Insects

Mix 2 oz lemon dish soap in 2 gallons water. Pour slowly over a 2'x2' area spanning green and brown grass. Wait 5 minutes. Collect surfacing insects in a zip-lock bag. Take to County Extension Office with a grass sample for free ID and treatment advice.

Step 2: If No Insects, Check for Fungus

Examine blades on the green edge of brown patches. Look for distinct spots: tan with dark borders (brown patch), hourglass lesions (dollar spot), or rust-colored powder (rust). Fungicides are pathogen-specific—misapplication wastes money and may violate regulations.

Step 3: Consider Professional Help

Fungus ID is tricky; treatments are expensive and sometimes restricted. A pro can diagnose, apply correctly, or recommend resodding/reseeding if cheaper.

Be your own lawn doctor: start simple (insects), escalate with evidence, and lean on free Extension expertise.