Water Mill keeps its windmill on the green and its old potato ground behind privet, and the light coming off Mecox Bay makes every lawn in town look like it has been painted. Israel Landscaping & Tree Services Inc mows and trims those properties through the long season, holding the edges sharp where turf meets drive, walk and hedge. Salt air and sandy soil make their own demands out here, and a lawn that stays even and green from Montauk Highway down toward the water is the result of showing up on the same day every week. Spring cleanups open the beds and fence lines; the fall work takes the leaves off before the cold turns the ground. Between them it is grass — and the pleasure of a yard that looks composed from the road.