October at Hammond Pond turns the oaks copper and drops half of them onto the lawns of Chestnut Hill. Rob Cerra Landscape Construction spends that stretch of the year in leaves — hauling them out, taking the grass down for the last cut, opening the beds so the turf goes into the cold clean. Earlier on it is the steady work: weekly mowing, crisp edges along the walks, the ragged corners tidied where the woods lean in. Properties that back onto conservation land are forever negotiating with the trees, and the negotiation is the interesting part of the job. When the last tarp goes in the truck and the lawn is bare and green again, that is the whole point of the day.