August lies heavy on Main Street, and the shade on Waltham Common is crowded by noon. Domenic Guerra Landscaping starts early for that reason — mowing while the dew is still down, trimming close along fences and hydrants, cutting a clean edge where lawn meets sidewalk. Beds get mulched, borders get shaped, and the clippings leave with the truck. In a city yard the difference between mown and finished is about ten extra minutes, and those ten minutes are the entire point. Lawn care in Waltham, Watertown, Newton and Belmont.