Late afternoon on the Brattle Street side of Cambridge is all filtered light — old maples leaning over the sidewalk, shadows sliding across clipped front lawns. Laipson Landscaping tends those yards: mowing, edging, hedge and shrub trimming, and the seasonal cleanups that keep a shaded lot from going ragged. Grass growing under big trees asks for patience and a careful height of cut, and here it gets one. Come November the leaf drop near Mount Auburn Street is worked through until the lawns are clear and the beds are put to rest. It is close-in, unhurried work for Cambridge and the towns just over the line.