The Nashua River bends past Ayer with a slow, brown patience, and Grove Pond holds the light long after the streets have gone blue. Hungry Wolf Tree & Landscaping Service keeps lawns along that low ground — mowing through the humid weeks of July, raking down the leaves in the short amber afternoons of October. When the wind swings and the snow arrives sideways off the open fields, the crew turns to plowing, opening drives and walks so a Tuesday can start on time. There is a plain satisfaction in a yard that looks cared for, and in a path shoveled all the way to the step. Ayer gets both from them.