Lawn and Turf: Dollar spot

Biology

Several species of fungi can cause fairy rings in lawns. Common symptoms may include a ring of dead grass with darker green grass and mushrooms on the inside and/or the outside of the ring, circular patches of darker green grass, or rings of mushrooms appearing with or without other symptoms. Mushroom rings commonly appear in the spring or fall when adequate moisture is present. The type of fairy ring which causes dead rings is the most damaging. The fungus feeds on decomposing organic matter in the soil and makes water penetration difficult. Fairy rings are more severe on sandy soil with low fertility. Grass inside the rings may be weakened or killed and replaced with weeds and weedy grasses. Fairy rings may disappear suddenly.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

• Provide proper culture, including deep, infrequent waterings and adequate fertilization.
• Rake and loosen soil in affected areas. Aerate soil and water the area deeply. A grass-type wetting agent can be used to help rewet the soil.
• After rewetting, reseed affected areas and fertilize and water properly.
• Remove the sod, mix soil in affected areas in the upper 6 to 8 inches of soil with a rototiller, and reseed or put new sod in the area.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

• Follow label directions when this disease has been diagnosed.
• Do not repeatedly apply the same fungicide or fungicides with the same active ingredient as tolerant strains may result.
• Carefully check product labels.

Approved Pesticides

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.

• ferti-lome F-Stop Lawn and Garden Fungicide
  Active ingredient: myclobutanil [EPA registration number: 7401-505]
• ferti-lome Liquid Systemic Fungicide II R-T-Spray
  Active ingredient: propiconazole [EPA registration number: 53883-184-7401]
• Spectracide IMMUNOX Multi-Purpose Fungicide Spray Concentrate
  Active ingredient: myclobutanil [EPA registration number: 9688-123-8845]
• This list may not include all products registered for this use.

Additional Images