Necrotic Ring Spot Occurrence: Late winter, spring, and fall. Most severe on Kentucky bluegrass, annual bluegrass, and creeping red fescue.
Irregular patches of grass with various shades of yellow, tan, or brown “rings” and green grass in the center. The size of the individual patches of dead grass range from 2-3 inches to 2-6 feet in diameter.
Conditions Favoring Disease Development: Cool weather and wet soil. Most prominent in three to four year old lawns.
Control: Maintain soil moisture to promote deep root growth with less frequency. Fungicides can be used to prevent ongoing growth. Usually multiple treatments are required and must be made prior to outbreak.
Top-dressing with ¼” organic compost can help to break down fungal activity.