Plant Amnesty founder Cass Turnbull grew up on a leafy lot in the Magnolia neighborhood. "There weren't any kids around, so I made friends with the yard," she says.

Her affinity for green things led her to a job at the Seattle Parks Department and then her own landscaping business before she settled into her life's work: educating people and organizations on how to care for the urban landscape.

As Plant Amnesty's president, she does everything from teaching pruning workshops to slapping a phony "Arrest Warrant" in fluorescent orange on the doorstep of a homeowner guilty of serious landscape infractions. "Reasons for Issuance" range from "MMP," or "Misdemeanor Mal-pruning," to "Reckless Endangerment," for such mistakes as planting a large tree under a power line, or a sun-loving tree in full shade.

Plant Amnesty began the Heritage Tree Program in part because of all the "sad tree" stories fielded by the nonprofit, which decided something needed to be done to alert the public to special trees.

It is not just the private, but governmental dismissal of trees that riles Turnbull. "We don't take trees seriously, and we don't defend trees seriously," she says of city tree policies. "Important work doesn't happen, because there's no central authority." Turnbull would like to see a "tree czar" to oversee protection of all city trees.

When asked why people who don't feel sentimental about foliage should care about their arboreal neighbors, Turnbull's big blue eyes grow even bigger. "Trees in your back yard are a utility," she says. "The urban forest stops smog, rain runoff, landslides, and makes oxygen. As tree advocate Don Willeke once said, we'd need trees even if they were ugly and smelled bad."

— Maria Dolan

Cass Turnbull is also author of "Cass Turnbull's Guide to Pruning" (Sasquatch Books, 2004).