By September the sun comes in low and sideways down Mendota's sidewalks, and every mowed row shows up like corduroy. Vandewyngaerde Lawn works those weeks with a mower, a trimmer and a good eye — grass held level, edges cut clean along walk and drive, concrete swept before leaving. Late-season lawns are a slower kind of green; they take a cut well and hold it longer. There is a quiet pleasure in the last pass of an afternoon, standing at the curb to check the rows before loading up. It is a small thing to give a street, and it shows all the way down the block.