The greater Phoenix metropolitan area predominantly falls within USDA plant hardiness zone 9b, characterized by average minimum winter temperatures ranging from 25F to 30F. Some outlying areas, particularly those at higher elevations, may experience temperatures that place them within zone 9a (20F to 25F). This zone designation is a critical factor in determining which plants are most likely to thrive in the region’s climate.
Understanding the local zone offers significant advantages for gardeners and landscapers. It provides a reliable gauge for selecting plant species that can withstand the typical winter conditions, promoting healthy growth and reducing the risk of plant loss due to cold damage. Historically, agricultural practices in the area have relied on an understanding of temperature tolerances, though the formalized zone system provides a more precise and readily accessible framework.
