A Saturday morning in Norwood sounds like a mower two streets over and a ballgame starting up at Endean Park. Martinez Landscaping is part of that sound from April into November: weekly mowing, string trimming, edging, mulch refreshed in the beds, shrubs kept in shape. Spring cleanups open the year and fall cleanups close it, the leaves off the grass before they mat down over it. What holds the whole thing together is rhythm — the same day, the same route, the same clean finish along the driveway. Norwood and nearby Westwood, Dedham, Canton, Walpole and Sharon.