First light on the Islands Expressway. The tide is running out past Oatland, herons stalking the flats, and the causeway is empty except for one truck and trailer headed east. LAWN TEACHER starts there and works the morning: mow, trim, edge, blow, move on. Grass on this side of Savannah grows in salt wind and sandy ground, so it wants a steady hand rather than a dramatic one — cut often, cut right, keep the beds clear and the borders sharp. Savannah and the eastside islands are the whole map.