Five Cool-Season Diseases to Watch

Disease Highlights: Five Cool-Season Diseases to Watch

1) Brown Patch
Appears as somewhat circular patches of brown, tan or yellow blighted grass from five inches to several feet wide. A dark edge known as smoke ring may surround patch in wet or humid conditions (often in morning) signifying active disease development.

Photo: Chazz Hesselein, Alabama Cooperative Extension System, Bugwood.org

2) Dollar Spot
Symptoms include sunken circular patches up to several inches in diameter. Patches turn brown to straw color and may eventually combine to form irregular shapes. Leaves can present yellow-green lesions with reddish-brown edges. Affected roots darken.

Photo: Mary Ann Hansen, Virginia Polytechnic Institute and State University, Bugwood.org

3) Melting Out & Leaf Spot
Melting Out is active in cool, wet spring; Leaf Spot in summer. Both appear as small reddish-brown or dark purple spots on leaves and stems that rapidly spread. Older spots become “eyespots” (with buff-colored centers and dark margins). Leaves eventually form patches of dead, thin, yellow grass.

Photo: William M. Brown Jr., Bugwood.org

4) Summer Patch
Symptoms initially resemble drought stress, presenting as small one- to three- inch patches of pale grass with leaves turning gray, brown or straw-colored. Patches may expand and leaves may develop white streaks in response to heat and root damage.

Photo: Mary Ann Hansen, Virginia Polytechnic Institute and State University, Bugwood.org

5) Fairy Ring
Appears as darkened arcs, rings or patches that are initially less than 12 inches in diameter, expanding in size each year. Can support fruiting bodies such as mushrooms and puffballs. Roots show orange discoloration and may have a strong mushroom odor.

Photo: Lester E. Dickens, Bugwood.org

Fungicides Can Help You Stay on the Winning Side

When necessary, fungicide treatment with products such as Nufarm Tourney® or 3336® F provide preventive and curative performance to combat a wide range of challenging turfgrass diseases. Always read and follow label directions.

Tourney® Fungicide is one of the most active fungicides on the market, controlling many difficult to control lawn diseases for up to 28 days while improving turf quality.

3336® F is a broad-spectrum fungicide with a systemic mode of action that is particularly effective on a wide range of diseases.