Turfgrass Disease Flowchart
Text: Turfgrass Disease Identification
Symptom: Distinct patches of yellow, light straw- or brown-colored turfgrass
IF patches are less than three inches in diameter, potential diseases include:
- Dollar spot: leaf spot lesions with tan- to straw-colored centers, or
- Nigrospora blight: tan- to white-centered lesions during warmer weather than dollar spot.
IF patches are more than three inches in diameter, potential diseases include:
- Large patch: circular patches up to several feet across, may have yellow to orange border, or
- Take-all root rot: irregular patches, eight to 24 inches wide; mix of yellow and dead grass.
Symptom: Rings or arcs of lush green to dead grass; mushrooms may be present.
Potential diseases include:
- Hydrophobic fairy ring: rings or arcs more than 15 inches wide; may repel water and have mushrooms, or
- Rhizoctonia leaf and sheath spot: rings less than 15 inches wide; narrow, consistent width; doesn’t repel water.
Symptom: No distinct patches are present
IF there are spots on leaves, potential diseases include:
- Rust: orange spots (or blisters) on leaves and orange rubs off easily,
- Bipolaris: red to purple leaf spots and and blotches widely ranging in size,
- Cercospora: narrow purple spots that turn oblong and irregular with tan centers and brown borders,
- Gray leaf spot: spots are oval to irregular with brown borders and tan to gray centers, or
- Anthracnose: reddish-brown to brown spots with yellow halo.
IF there are no leaf spots, potential diseases include:
- Slime mold: grass is covered with slimy or crusty growth that is easily removed, or
- Pythium root rot and/or nematodes: scattered yellow leaves and general decline.