April arrives in Cornwall the way it always has — up from the Hudson, over Firthcliffe, greening the old millrace banks a week before anybody's lawn is ready. Green Cornwall Landscaping takes the season from there with spring cleanups, mowing, trimming, edging and the weekly rhythm that follows. There is one particular week when a tired yard turns and holds its color, and getting a place to that week is most of the craft. Nothing exotic about it: the right height, the right day, a clean line along the walk. By May the town is green and these lawns keep pace.