The first mow of May in Waterloo comes with the dew still down and marsh air drifting in from the Montezuma flats east of town. GrassMan Lawn Care starts the season there and keeps it rolling with mowing, string trimming, edging and cleanups at both ends of the year, on the yards between the village and the black-dirt fields. Grass on this ground grows in a hurry once the nights ease up, and the trick is never falling a week behind it. By July the lawns hold a green they only get here, between two lakes with the water table close underfoot. A yard cut level and swept of clippings looks twice its size, and that never stops being satisfying.