Where Sterling runs down toward Pachaug and the oaks lean in over Route 49, a lawn is something you carve out and then defend. TYLER'S TREE & LANDSCAPING SERVICE takes on that yearly argument — spring cleanups, mowing on a steady rotation, trimming around posts and stone, edging so the shade line and the sun line both look intentional. April here is mud, and then, almost overnight, green. By the time the ponds off the back roads have warmed, the yards along them are cut, cleared and holding their shape. Sterling, Oneco, Voluntown, Killingly and Plainfield are all within reach.