To determine your gardening zone, you can use the USDA Plant Hardiness Zone Map. The 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 use the map, locate your area on the map and find the corresponding zone. For example, if you live in Chicago, you would be in zone 5. Its important to know your zone because it can help you choose plants that are suitable for your climate and will thrive in your area.