Lawn diseases, fungi Summer Lawn Diseases

Brown patch: This disease is prevalent during moist, hot weather on over-fertilized lawns.  Brown patch, also known as rhizoctonia blight, is most active when grass remains wet and temperatures reach 80 to 90 degrees Fahrenheit. Look for: Dark, water-soaked looking grass turning into browned-out circular areas several inches to several feet in diameter. Some green leaves may persist within the patch, and roots remain intact. In addition, blades may have irregular ash gray lesions with a dark brown margin running along one side. On short turf, a 2-inch “smoke ring” of gray mycelium may encircle the patch in early morning.  Read more »
 
 

Lawn issues might be a dog rather than disease Is It Really Lawn Disease?

The best time to assess your turf’s state of health is before mowing. As you pick up fallen twigs or remove other items from the lawn, you should take a careful look at any areas that appear wilted, off-color or stand out from their surroundings.  If you do note changes, it might not be disease.  For instance, brownout of a cool-season grass during high summer is likely just summer dormancy, which is the grass’s protective response to drought and heat.  Dull, wilted, bluish gray turf is the grass’s signal that it needs water, and general yellowing and stunted growth may be a lack of iron or nitrogen. Read more »
 
 

fairy-ring-lg Identifying Diseases

Many diseases will leave bleached-out, dead turf.  When this occurs you not only lose the grass, but you also lose the opportunity to determine what caused the problem.  Diseases are progressive in nature, especially during hot, humid weather. It is important to check your lawn regularly if you want to spot disease symptoms early on.  Look for spots or banding, color changes, or signs of decay on grass blades.  When you examine affected turf look at its shape, size, color, and texture. Does it feel slimy or dry?  Read more »
 
 
 

Spring through fall lawn diseases Spring-Through-Fall Lawn Diseases

Fairy Rings: Caused by more than 50 varieties of fungus, the rings vary in size and appearance but all form in damp conditions in soil that is high in woody organic matter, which is usually from buried debris or tree stumps. Look for: Rings of fast-growing, dark-green grass with centers composed of weeds, thin turf, or dead grass.  Midsummer and fall rings are more apt to be composed of dead grass.
Management: The rings are difficult to remove unless completely dug out to a minimum depth of 1 foot.  Aerating the ring area to improve water penetration and fertilizing to minimize color variation are helpful. Read more »
 
 

Fall through spring lawn diseases Fall-Through-Spring Lawn Diseases

Typhula blight (gray snow mold):  Strictly a cold-weather disease, typhula blight appears where snow cover has melted, especially in areas where snow has drifted or been piled. Look for: Irregular 2 to 24 inch patches of bleached-out, matted turf covered with moldy, grayish white mycelium.  Embedded in the leaves and crowns of infected plants you will see tiny black or orange-brown spherical sclerotia (hard fungus bodies). Management: Avoid heavy nitrogen fertilization in late fall to allow new growth time to harden off before winter.  Keep thatch to a minimum and grass height lower as winter begins.  Read more »