A hardiness zone (also referred to as Growing Zones or Planting Zones) is a geographic area defined as having a certain average annual minimum temperature, an important factor relevant to the survival of many plants. The original and most widely used system, developed by the United States Department of Agriculture (USDA) as a guide for landscaping and gardening, defines 13 zones by long-term average annual extreme minimum temperatures. It has been adapted by and to other countries (such as Canada) in various forms. Plantmaps Hosts Interactive Maps of Hardiness and Growing Zones for all US States, Canadian Provinces and Many Countries Around the World. Maps and Data for the US are based on the USDA 2023 Hardiness Zones. We also maintain maps for the 1990 and 2012 USDA Hardiness Zones. Canada Hardiness Zones are based on zones defined by Natural Resources Canada and cover the climate period of 1981-2010. Hardiness zones maps outside the US and Canada where created by Plantmaps using climate data from the period of 1991 to 2020;