Pink Patch Fungicides

Pink patch is a cool, humid-weather disease of creeping bentgrass, fine fescues, perennial ryegrass, and sometimes dormant bermudagrass. It is related in appearance to red thread but is caused by a different fungus.

What to Look For

Small pink or tan patches develop with gelatinous pink growth on leaves when wet. Unlike red thread, pink patch does not form the distinct red antler-like strands that project beyond leaf tips.

Why It Develops

Mild temperatures, high humidity, long leaf wetness, low fertility, and slow-growing turf favor symptoms.

Reduce Disease Pressure

• Correct low nitrogen where soil and tissue testing support it.
• Water early and improve airflow.
• Mow regularly with sharp blades and remove heavy infected clippings.
• Improve overall turf density and reduce prolonged canopy moisture.

What University Research and Extension Guidance Says

Kentucky reports that treatment is usually unnecessary. When disease is unacceptable on high-value turf, its review found activity from several fungicide groups but specifically reported flutolanil ineffective against pink patch. That distinction is important because flutolanil performs well on several other Rhizoctonia-related diseases.

Choosing and Using a Fungicide

Use the products below as a starting point, then match the active ingredient, FRAC group, turf species, use site, timing, rate, interval, and watering directions to the current product label. Preventive or very early applications are usually more reliable than rescue treatments after extensive injury. Rotate effective FRAC groups and combine fungicides with the cultural changes above.

Research and label note: University research may identify useful activity even when a current product label does not name this disease. That is research evidence, not a label direction. Apply a product only where the turf or application site and use pattern are permitted, and follow the complete label and applicable state requirements.

University sources: University of Kentucky: Chemical Control of Turfgrass Diseases 2024; Penn State Extension: SDHI Fungicides for Turfgrass Diseases.