Glenn Keator, a California plant specialist, is author of Trees of the San Francisco Bay Area (UC Press), The Life of an Oak, Plants of the East Bay Parks, and Complete Garden Guide to the Native Perennials of California. Alrie Middlebrook is the founder and president of Middlebrook Gardens in San Jose, California, a design company that specializes in California native gardens. She is author of Eating California. They have been hiking California and teaching classes on California native plants for thirteen years.