Organic lawn care; re-routing bathroom fan

Landscape contractor Roger Cook visits Harvard University to learn about the new organic lawn-care program; he shows host Kevin O'Connor how to make his own "compost tea." Then, Roger and Kevin, along with general contractor Tom Silva and plumbing and heating expert Richard Trethewey, ask, "What is it?" Afterward, Tom helps a homeowner prevent mildew in his attic by re-routing a bathroom fan that was improperly vented near a soffit.