To determine your garden zone, you can use the USDA Plant Hardiness Zone Map. This map is based on the average annual minimum winter temperature, divided into 10-degree F zones and further divided into 5-degree F half-zones. To find your zone, locate where you live on the map. The map is available on various websites, including the USDA website, Gardening Know How, Plantmaps, and The National Gardening Association.

For example, if you live in Mesa, Arizona, you are in USDA Hardiness Zone 9b.