By September the water off Prybil Beach goes glassy in the mornings and the light comes in at an angle that flatters a well-kept lawn. ELIM LANDSCAPING is out in it, mowing, running the edge along walks, trimming close to walls and posts, clearing the first leaves down. North Shore grass catches a second wind in early fall, thickening once the heat finally breaks. A yard cut in that window holds its stripe for days. Glen Cove's shoreline streets and the blocks stepping up from them fill out the week.