In October the oaks along the Concord River go copper, and Billerica starts letting go of its leaves onto every lawn from Nutting Lake to the old canal line — which is when Killilea's Landscaping & Design arrives to rake and clear and hand a yard back to itself, breathing and green again. The rest of the calendar runs the same honest way: mowing, fertilizing, aeration, weed control, spring cleanups, and irrigation set so the water lands exactly where it ought to. They also build the parts that stay put — patios and walkways, retaining walls, landscape lighting that makes a back yard somewhere worth sitting after dark — and they do the excavation beneath it all, site prep and land clearing and drainage that keeps one soggy corner from spoiling a whole season. Then February comes sideways down the Route 3 corridor, and there is snow removal around the clock, a lot pushed open and a walkway cut before the first headlights turn in. Homes, office parks, schools and medical centers across Billerica, Chelmsford, Tewksbury, Bedford, Burlington, Wilmington, Andover and out through Middlesex County — and the real satisfaction is always the same one: an edge that holds its line, a drive that's clear, ground that plainly looks tended.