This edition of the USDA Plant Hardiness Zone Map (PHZM) is GIS (Geographic Information System) based for the first time. This is also the first USDA PHZM that is specifically designed for the Internet. It enables viewers to examine plant hardiness zones at a much finer scale than ever before. For the first time, a very sophisticated algorithm was used to interpolate low-temperature values between actual weather reporting stations. A personal ZIP Code zone finder is also included with this version of the map. Simply type your ZIP Code in the proper box and your zone will be reported.