April along the Black Hall River is mud and green arriving at once — marsh grass coming back, peepers going at dusk, and every lawn in Old Lyme waking up ragged from the winter. Yankee Tree LLC works the yards through that turn, mowing and tidying until the grass runs even and the edges read clean from the road. It is plain work with a visible result, which is most of its appeal: you can stand at the mailbox and see exactly what an afternoon accomplished. This town runs from tidal marsh to back-road woodlot, and no two properties want quite the same thing of a mower. Week to week, that steadiness is what keeps a shoreline lawn looking like somebody is home.