
Identification Guide on Lawn Disease


Brown patch
Brown patches in your lawn typically measure from 5 to 10 inches in diameter and are brown or tan.

Dollar spot
A dollar spot(s) may appear to be sunken, circular patches in various areas of your lawn. They may appear yellow or red.

Fairy ring
A fairy ring typically looks like a circle that has rings around it that are either dark green or brown.

Fusarium patch
These patches are yellow or red and measure 1 to 6 inches in diameter. They typically resemble smoke rings.

Gray snow mold
These patches will appear after the latest snow melt and are light brown or gray.

Large patch
A large ring or patch of dead grass that has a smoke ring look and brown borders typically measure 10 feet in diameter.

Microdochium patch
This type of patch is similar to the gray snow mold patch but appears in a yellow, tan or salmon color.

Necrotic ring spot
Thinning, yellow grass may appear and can expand up to 3 feet in diameter.

Powdery mildew
Appears on the leaves of grass then enlarges and turns into a gray or powdery appearance.

Red thread and pink patch
Patches appear in the grass and are red or pink. They can grow up to 2 feet in diameter.

Rusts: crown, leaf, stem, and stripe
Light yellow flecks initially on the leaf blades and sheaths. Typically occur in early spring through fall depending on the location of the turf.

Leaf spot/Melting-out
Purplish-brown to black spots with tan centers on the leaf blade and sheath. In severe cases, almost all of the leaves and tillers die.

Pythium blight
Appears suddenly during hot, humid weather. Greasy, brown circular spots that are initially about 3/4 inch to 2 inches in diameter. Rapidly enlarge in size.
