Support WBURGuerrilla Grafters Bring Forbidden Fruit Back To City TreesPlay03:00Download AudioLonny ShavelsonApril 07, 2012 ShareGuerrilla grafter Tara Hui grafts a fruiting pear branch onto an ornamental fruit tree in the San Francisco Bay Area. She doesn't want the location known because the grafting is illegal. (Lonny Shavelson for NPR)