Dunback Meadow holds the low wet middle of Lexington, and on a July evening the fireflies rise out of it and drift into the yards along its edge. Seasons Four mows those yards, trims what the mower cannot reach, edges the walks and drives, and runs the lawn cleanups that keep a property from getting away from itself. Midsummer here swings between downpour and drought inside the same fortnight, so cutting height and timing are half the job. A lawn that comes through August still dense and green was decided back in June. Standing at the curb at dusk, looking back at an even, unbroken lawn, is the reason to bother doing it well.