On Lynn's western edge the Saugus River opens into marsh grass, and the light out there shifts with the tide twice a day. GRL Landscaping & Tree Services works the neighborhoods backed up against that low ground, mowing and trimming through the warm stretch and edging drives and walks so the yards keep their shape. Winter comes across the marsh with nothing at all to slow it down, and then the crew is plowing, opening paths and salting where the wind keeps packing it back in. Cleanups close out the fall before the cold sets. Two halves of the year, two sets of tools, one city.