August on the older streets near Garfield Park is nearly all shade, maples and elms grown together overhead and the light coming down in coins. Black Birch Lawn Mowing Inc. cuts those lawns knowing shade grass is a different animal, thinner and slower and quick to bruise if the deck rides low. Mowing on a set schedule, trimming close to trunks without scarring bark, edging the walks, and hauling off what the canopy sheds. Aurora's tree streets look their most themselves when the grass beneath them is even and the beds are dark and clean. Late in the day the engine goes quiet and the block settles into that particular green stillness.