This map of climate zones will help you select plants for your garden that will survive a typical winter in your region. The United States Department of Agriculture (USDA) developed the map. The ones are based on the average lowest temperatures across the United States. Zone 1 is the coldest region and Zone 11 is the warmest.
Plants are often classified by the coldest temperature and zone they can endure. You will find this notation on plant labels, in plant catalogs, and plant reference books, and online. For example, a plant hardy for Zone 6 will survive where winter temperatures drop to -10°F (-23.3°C). A plant hardy to Zone 8 will die long before it is that cold. A plant hardy to Zone 8 growing in Zone 6 will need to be replaced each year. Plants rated for a range of hardiness zones can usually survive winter in the coldest region as well as tolerate summer heat of the warmest one.
To find your hardiness zone, bot the approximate location of your community on the map, then match the color band marking that area to the key.