There is a week each November when the Concord River turns slate under the old mill-town bridges and the last of the oak leaves come down over Billerica's yards all at once — and that is the week the mowers give way to plow blades, the work turning with the weather rather than against it. Through the green months, Russell Landscaping keeps properties in trim: mowing and seasonal cleanups, hedge trimming, mulch delivered and laid dark against the beds, irrigation maintenance, fertilization and weed control, lawn renovations, and tick and mosquito spraying for the yards that back up to the pine woods. The heavier work leaves a longer mark on a place — landscape design, hardscaping with patios, retaining walls and stone walkways set to sit level long after the setting, excavation and land clearing, foundation digging, stump removal, dumpster rentals. Come winter, commercial snow management means lots and drives opened in the blue hour before the first headlights swing in off the road. It is residential and commercial work across Wilmington, Tewksbury, Billerica and the towns around them, and its whole reward is visible from the street: a crisp edge, a clear lane, a yard that holds its season.