Tuesday in midsummer, and the route runs the way it always runs. K & L mowing works Mount Vernon block by block — cut, trim the fence line, edge the walk, blow the clippings off the concrete, move on. No mystery in it, just a lawn held at the right height all season instead of rescued twice a year. The front yards here are small enough that a week of growth shows and a fresh cut shows more. Doing the ordinary thing on the ordinary day is the whole trick.