Hardiness zones are areas across the country whose average coldest winter temperatures are the same. They are shown in bands on the USDA Hardiness Zone map and numbered Zone 1 (the coldest) to Zone 13 (the warmest).
They’re important because - used alongside the hardiness ratings attached to individual plant varieties and noted on plant tags, websites and in catalogs - it’s easy to see which plants will survive the winter in your area.
