Brown Patch Disease – In Fescue
Q: I have this condition all over my fescue yard. Could you tell me what it is?
A: It’s almost certainly brown patch disease. The circular spots with a green center give it away.
Brown patch favors high relative humidity as well as temperatures of over 80°F during the day and over 60°F at night. It also occurs in areas that experience more than 10 hours a day of leaf wetness for several consecutive days.
Over-fertilization and over-watering are associated with the disease. Brown patch infestation is more severe when the turf is cut to a height less than the optimum for the turf-grass being grown.
Be sure your management of your lawn is correct before reaching for a fungicide.
Propiconazole (click for sources) and thiophthanate-methyl (click for sources) are effective fungicides but read the label to be sure the product you choose can be applied to lawns.