On a clear evening the Shawangunk ridge goes violet along the western sky, and every lawn in Montgomery holds that light for a few minutes before it goes. Avila's Landscaping likes finishing a mow right then — grass even, borders tight, the last trimmings blown off the walk. Through the warm months it's mowing, trimming, edging and cleanup across the village and out along the roads toward Walden. Through the cold ones it's plowing and shoveling, driveways and walkways cleared so a house is never cut off from the road. This valley rewards both kinds of attention.