Late in the day at Memorial Park the shade of the big trees lies across the grass in long stripes, and suddenly every mown lawn on the street shows its own striping too. LawnBusters Landscaping chases that look — mowing, string trimming, clean lines along the walks, mulch worked into the beds, leaves hauled clear in autumn. Once winter takes hold the same trucks head out with plows and spreaders for driveways, walkways and lots. Most of the route sits inside Reading, with regular stops in Wakefield, Stoneham and Melrose. The satisfaction is small and repeatable: a straight line where the lawn meets the pavement, week after week.