There is a geometry to a well-kept lawn, and Mount Vernon's newer streets show it best at dusk, when low sun makes every mowing stripe stand up. Lawn Perfection Inc works toward exactly that — deck level, passes parallel, the turn at the end of each row tucked in so the pattern never breaks. Mowing, trimming, edging, then blowing the hard surfaces off, in that order, every visit. The most satisfying part is the border: a vertical cut where grass stops and concrete starts, sharp as a folded page. June evenings here stay light until nine, a long and generous window for standing back to look at a yard just finished.