Landscaper Roger Cook and arborist Matt Foti plant a blue spruce in the backyard of the Winchester, Mass., house; homeowner Bruce Leasure and host Steve Thomas explore media-room options; and plumbing-heating expert Richard Trethewey shows Thomas three polyurethane tanks that will hold rainwater for garden reuse. Meanwhile, carpenter Norm Abram visits Vermont coppersmith Larry Stearns, who is fashioning a “This Old House” weathervane. On “Ask This Old House”: Contractor Tom Silva shows Thomas how to make a sawhorse and assesses those that are commercially available; Trethewey installs a frost-proof outdoor faucet; and Cook advises a homeowner on how to compost leaves.