Hardiness Zones

Assuming you provide the right amount of light, water and nutrients for your plants, the one remaining intangible in ensuring plant growth is temperature, especially cold temperatures. The United States Department of Agriculture (USDA) has developed a standardized Hardiness Zone Map to assist you in identifying the average annual minimum temperature for your area. Once you know your Hardiness Zone, you can then pick those plants that are best adapted to survive through the Winter.


The following pages describe the methodology used to develop Hardiness Zone Maps, the recent update to the United States Department of Agriculture (USDA) Hardiness Zone Map and alternative approaches to determining the optimum growing climate for a plant. There are few authoritative references on the Internet that provide a complete discussion of Hardiness Zone Maps, so the following is an attempt to consolidate the sources.

  1. What is a Hardiness Zone?
  2. What is my Hardiness Zone?
  3. The 2012 USDA Hardiness Zone Map and Its Predecessors
  4. Alternative hardiness zone maps
  5. Evolution of hardiness zone maps for Florida