Go organic to build the beneficial microbes in the soil. Spread a thin layer (1/2") of compost or for faster results corn meal at 20 lbs./1,000 square feet. Spray the problem area with Garrett Juice plus garlic tea. Potassium bicarbonate at 1 rounded tablespoon per gallon can be added for additional control. Broadcast cornmeal at 20 lbs./1,000 square feet.