When the sycamores along Memorial Drive leaf out, Cambridge turns green in a hurry and every small yard between the river and the squares wants attention. Boston Landscaping & Painting takes the lawn work: mowing, edging along brick and granite, trimming, mulched beds and seasonal cleanups. City lots run tight and shaded, so the cutting goes in short passes and the trimmer does most of the shaping. A yard here gets measured in feet rather than acres, which makes the edges count that much more. Cut close and edged true, a strip of grass off a Cambridge sidewalk looks deliberate.