Atwood LawnCare

Q: Why does my lawn have 2 inch circular brown spots?

The problem may be a fugus called Dollar Spot.

What you’ll see… are tan lesions, or yellow spots on the blades of the grass. These spots are usually surrounded by a reddish brown border. The tan band, or lesion, is often narrower in width than the leaf, resulting in the lesion taking on an “hourglass” shape. As the grass dies and the infected areas enlarge, light straw-colored spots in 2 to 3 inches in diameter appear in the lawn. If left unchecked, the spots may merge and form large irregular straw-colored patches.

The reason for the problem… is caused by the fungus Sclerotinia homoeocarpa. The fungus produces resting bodies called stoma which may live for long periods on grass clippings, in thatch, or in soil. The fungus favors temperatures between 65 and 85 degrees with periods of leaf wetness from dew, rain or sprinkler irrigation. Prolonged wet foliage is a key factor. Growth of dollar spot fungus is inhibited when temperatures exceed 90 degrees.

You should… keep the grass growing and healthy by:
- Water the lawn regularly to keep the grass growing, however do not over water.
- Water in the morning or midday so the leaf blades dry as quickly as possible.
- Mow the grass to a height of 3 to 3 ½ inches. Make sure the mower blades are sharp. Never remove more than 1/3 of the grass at a time.

We can help by…
- Continuing to provide a sound fertilization program.
- If diagnosed early chemical control can be helpful. This requires 2 visits performed 21-30 days apart.
- Core aerate the lawn once a year (spring or fall) to help reduce thatch buildup and improve soil conditions.