By mid-July the fields around Owosso are shoulder-high and the afternoon builds thunderheads off to the west that you can watch coming for a solid hour. Central Michigan Mowing L.L.C. works ahead of that weather — mowing, trimming, edging, blowing the clippings off the drive — because there is a window between the heat and the rain and the whole day gets arranged around it. Cut grass smells better in that heavy air than at any other time of year. The reward is simple and it lasts about a week: a lawn lying flat and even, lines running true to the street, borders sharp where they meet the sidewalk. Then it rains, everything starts growing again, and you come back.