There is a boardwalk at the Patterson Environmental Park that carries you out over the wetland, and in July the grass on either side of town grows faster than anyone quite believes. Pattersons Lawn Service works in that humid, generous stretch of the year — mowing on schedule, edging along walks and drives, trimming out fence lines, carrying clippings away. Valley air makes turf grow in bursts, and staying ahead of those bursts is the whole discipline of the season. A lawn cut on the right day looks even and unhurried; cut a week late, it never fully recovers its line. They would rather come back sooner than explain that later.