McKnight's avenues were laid out for shade, and a century on the old maples still throw canopy clear across the pavement. Lawns underneath them are their own puzzle — thin light, heavy leaf fall, roots riding close to the surface — and ArborTech Tree Services, LLC mows, trims and cleans them up right through the growing months. When the leaves are down and the branches go bare, the same trucks return with plows for the driveways and front walks of those tall Victorian houses. There is a particular pleasure in a shoveled path between two snowbanks, running straight to a painted porch. The work changes with the calendar; the streets stay exactly where they are.