Brown Patch is a turf type disease that is running rampant in lawns throughout Southern Illinois this year. What appears to be circular, or even irregular shaped, browning spots in your lawn is probably really a fungus that has developed in your turf. It is caused from over-saturation of turf areas and high night-time temperatures and humidity. The 5 days of constant rain from tropical storm “Bill” this mid June, gave lawns the ugly look of these browning spots.
Products such as fungicides can be applied and help to stop the spreading of the fungus, but often time it is too late. The fungus can literally start and thrive over night and is hard to control unless you are applying a fungicide as a preventative. Re-application of the fungicide should be applied at a 7-28 day interval, but it is important to always read the product label and follow the instructions as every product is different.
Items to remember and to help prevent this outbreak are to water only early in the morning and keep your turf cut a reasonable height. It may take weeks for the damaged turf to recover. Greening of new or existing turf to fill back in the dead looking spots may take time. Many of lawns will need to be core aerated and overseeded in the Fall to help thicken the turf back up.