Photo by A. H. McCain
Photo by Ali Harivandi
Photo by Bobby Joyner, ChemLawn Corp.
Click on images to enlarge.
Annual bluegrass (a
common weed in turf), Kentucky
bluegrass, red fescue, tall
Dollar spot begins as small, circular spots 1 to 2 inches (2.5 -
5 cm) in diameter. Spots are straw colored or have a bleached appearance
and merge together to form large, irregular areas. Individual leaves
appear water-soaked, often exhibiting 2 reddish bands across the
leaf in an hourglass shape. Fine, white, cobwebby threads may be
seen in early morning.
Conditions favoring disease
Dollar spot appears during the spring and fall months in California
and is favored by moderate temperatures (60° to 80°F).
Excess moisture, water stress, fog, or thatch buildup can also contribute
to disease development. Dollar spot survives in the soil as hard,
dark structures called sclerotia.
Prevention and management
Apply fertilizer at the recommended
rate for your turf species. Follow proper irrigation
practices. Reduce thatch and maintain
air circulation. Compost top dressings may suppress the disease.
Increase your mowing height to
the tallest recommended for your turf species. If dollar spot has
caused a problem in previous years, a fungicide may be useful.
Apply it in the early spring or fall before symptoms occur.
For more information on lawn diseases, refer to:
Pest Notes: Lawn Diseases:
Prevention and Management