Windham Center on a July evening: the mowers have shut off, the heat is letting go, and the fields toward Dundee Pond hold their color right up until dark. Green masters keeps lawns through that stretch of the year — weekly mowing, string trimming, crisp bed edges, mulch, and the cleanups that open and close a Maine growing season. Grass here comes on fast in a wet June and then wants steady attention clear through the last warm week of September. The measure of the work is simple: even height, straight edges, walks and drives blown clean, nothing left behind but the smell of it. A small thing, repeated well, all summer long.