About Our Clickable Species Maps

USDA Hardiness Zones

  • This USDA plant hardiness zone map is based on USDA Miscellaneous Publication 814, "Plant Hardiness Zone Map," which was revised in 1965 and more recently in 1990.
  • Zones represent average annual minimum temperatures, in 10°F increments.
  • Ornamentals are species (not varieties) that are commonly planted.
  • Clicking on a state generates a listing of native and naturalized species for that state.
  • For our purposes, zonal subdivisions in the original map have been combined.
  • For the original map, along with additional information, please visit the National Arboretum


North American Floristic Regions (Biomes)

biome map


Last Updated: April 2010 Contact Us Photo Use



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