Common Lawn Diseases

Snowmold

Snowmold is most common to Kentucky Bluegrass and Fescues in regions where snow falls and sits on the lawn for extended periods of time.

The best prevention for snowmold is to aerate often. Improving water drainage, raking leaves off lawn's surface. Put your lawn on a regular fertilization schedule.

Brown Patch

Brown Patch is most common to Kentucky Bluegrass, and ryegrasses in regions with high humidity and/or shade. Brown patch commonly starts as a small spot and can quickly spread outwards in a circular or horseshoe pattern up to a couple of feet wide. Often times, while expanding outwards, the inside of the circle will recover, leaving the brown areas resembling a smoke-ring.

The best prevention for brown patch is to have your lawn aerated regularly, reduce shade to effected areas, and to put your lawn on a regular fertilization schedule.

Dollar Spot

Dollar spots are most common to Kentucky Bluegrass in humid climates. They get their name from their small silver dollar-like shape and usually look brown or straw-colored in appearance. Dollar spots tend to thrive during drought conditions with heavy dews and in those lawns with low levels of nitrogen.

The best prevention for brown patch is to have your lawn aerated regularly, water well in the morning hours, remove excess thatch, to put your lawn on a regular fertilization schedule.

Fairy Rings

Fairy Rings can grow in most grasses, and are distinguishable by circular rings filled with fast-growing, dark-green grass. Around the perimeter of the ring, the grass will typically turn brown and often times grow mushrooms. Fairy rings typically grow in soils that contain wood debris and/or old decaying tree stumps.

The best prevention for fairy ring is to aerate the diseased area, water well in the morning hours, remove excess thatch, to put your lawn on a regular fertilization schedule

Rust

Rust gets its name from the orange, "rusty" appearance it gives leaf blades. Most commonly effecting ryegrasses and Kentucky Bluegrass, rust tends to flourish in conditions of: morning dew, shade, high soil compaction, and low-fertility. The best way to check for rust problems is by taking a white tissue or paper towel and rubbing a few grass blades through it. If an orange color remains, then it's usually rust.

The best prevention for rust is to have your lawn aerated regularly, water in the morning hours, reduce shade to grass, mow more frequently and bag grass clippings; and put your lawn on a regular fertilization schedule.

Grease Spot

Grease Spot can effect all grasses in humid climates and can be recognized by the slimy-brown patches that often have a white, cotton-like fungus around it. Grease Spot gets its name for the "greasy" appearance it makes while matting together and can appear in streaks across the lawn.

The best prevention for rust is to have your lawn aerated regularly, water in the morning hours, reduce shade to grass, mow more frequently and bag grass clippings; and put your lawn on a regular fertilization schedule

Red Thread

Red Thread is most common to Fescues, Ryegrasses, and Kentucky Bluegrasses during times of moist and cool weather. Red Thread gets its name from the pinkish-red threads that form around the leaf blades and bind them together. Eventually, the affected grass will turn brown and the red treads will be most visible when wet.

The best prevention for Red Thread is regular aeration and remove thatch. Mowing to proper levels, reduce shade on lawn, and put your lawn on a regular fertilization schedule. Including potassium in the fertilization program may help mildly cases.

Powdery Mildew

Grass looks as though it is sprinkled with flour. Kentucky bluegrass and shade areas are the most susceptible. Grass will wither and die.

Water only in the morning; reduce shade by pruning, aerate and check drainage in the area.

Pythium Blight

Irregularly shaded spots of wilted brown grass. Cobweb-like mass of fungus on moist nights or mornings. Patches cluster to form streaks a foot or more wide

Do not over water and don't mow when grass is wet.

Fusarium Blight

Light green patches that spread, turn reddish brown and then die. Caused by a soilborne fungus, often in combination with other pathogenic fungi. Primarily attacks Kentucky bluegrass.

Usually occurs in hot, dry weather. Begins as a small spot, then grows until it kills the grass.

May require a fungicide application. Maintain a good watering schedule.

However, once symptoms are noticed, it's usually too late to control the disease for the current season.

Leafspot-Melting Out

Brown to purple lesions (spots on blades. Irregular dying areas of grass lesions on grass in margins of dead area. Caused by excess nitrogen fertility and possibly excess thatch buildup. Usually affects cool-season grasses.

Aerate and detach lawn. May require a contact fungicde when leaf spot is first noticed.

Leaf Smut