The major fungus problem in May is Red Thread. Red Thread is an indication of Nitrogen deficiency. Just apply a higher nitrogen fertilizer and the turf will recover and grow out of the disease
If you market tick control this application will be a money maker. May is a good time for a first application of Turf Pro Bifen I/T which is an economical and effective tick control application as well as controlling all other surface insects. 1.0 ounce active ingredient per 1,000 square feet will give control for up to 30 days.