Common Lawn Diseases

Brown Patch

• Brown patch is a lawn disease causing brown patches approximately 6 to 20 inches in diameter. These patches may have a purple or gray ring around them or tan spots on the leaves. This is a fungus that typically affects Kentucky bluegrass, ryegrasses, fine fescues and tall fescue during hot weather. Avoid overwatering your lawn and ensure it has sufficient drainage. Using a nitrogen-based fertilizer too often increases the risk of brown patch.

Pythium Blight

• Pythium blight infects your lawn displaying irregular spots in the grass during warm, humid weather. The spots may have a slimy or greasy appearance initially. The grass eventually dies, becoming dry and brown. Overwatering and excessive fertilization contribute to the problem. Do not water your lawn at the end of the day or leave it wet overnight. If it is hot, avoid mowing when it is wet. Be careful about the amount of nitrogen-based fertilizer that you apply to your grass as well. You may also opt for commercial fungicides.

Summer Patch

• Summer patch is a fungal disease that occurs in hot weather. Symptoms include yellow spots approximately 6 to 12 inches in diameter on your lawn. The grass in these spots usually becomes thin, and the surrounding portions may have a bronze tint. If hot weather persists, the entire area may die and weedlike grasses grow in its place. Watering your lawn in moderation and improving its drainage prevents this infection.

Fairy Rings

• Fairy rings are a circle of toadstools or puffball mushrooms surrounding a patch of green grass. These rings may have a diameter as large as 60 feet and often reoccur in the same spots every year. However, they usually expand in size each time they appear. As soon as you spot the mushrooms, rake the area to remove them because some varieties are poisonous. Increase your watering and fertilization helps even out the length of the grass.