C. COLSTON BURRELL has gardened in different climates across the United States, so he's included plants that thrive in many zones, from Maine to California. He holds a master's degree in horticulture and Master of Landscape Architecture degree from the University of Minnesota. He's a lifelong gardener, garden designer, photographer, and teacher and is the author and coauthor of numerous books, including Rodale's Illustrated Encyclopedia of Perennials, which has sold more than 500,000 copies.