October along the Arnold Arboretum turns Roslindale gold and then, within a week, turns it into work. FH LANDSCAPING CORP. moves through the fall with rakes, blowers and truckloads out — leaf removal, cutbacks, and a last mow taken low enough to carry the lawn through winter. The rest of the year runs steadier: weekly mowing, clean edges along walks and drives, mulch renewed once the beds start to fade. Boston yards tend toward odd shapes, sloped and stone-walled and hemmed in by neighbors, and each one asks for its own line. Done right, the property looks intentional from the sidewalk.