The first warm week of April, the grass over on the Natick side of West Warwick comes up all at once, as if it had been waiting behind a door. Lambert Landscaping And Property Services opens the season with the part nobody enjoys — winter sand off the walks, matted leaves out of the corners, ragged edges cut back to a line. Then the mowing starts and holds all summer, week after week, with trimming and edging on every visit. Small lots, larger properties, the odd slope behind a mill house: they all get the same passes. By June a lawn kept this way looks less like it was mowed and more like it simply never grew wild.