USDA ZONES

There are 11 Hardiness Zones created by the USDA (United States Department of Agriculture).

The USDA plant hardiness map divides North America into 11 hardiness zones. Zone 1 is the coldest with zone 11 being the warmest, with zone 11 being a tropical area found in Hawaii and southernmost Florida. In between, the zones follow a contoured pattern across the continent. There are some sporadic variations, and the zones account only for the coldest tempertures in each area.

CLICK ON THE MAP TO ENLARGE

THE SUNSET ZONES

There was a 24-zone climate system created 40 years ago by Sunset Magazine, that covers 13 Western states and are much more precise than the USDA's, for the Western region. The Sunset map has since been expanded to 33 zones and includes a more precise system of measurements for your plants. They factor in winter minimum temperatures and summer highs, lengths of growing seasons, humidity, and rainfall patterns to provide a more accurate picture of what will grow in these zones.

If you live in the western U.S., you'll find that western gardeners and facilities usually refer to the Sunset climate zones rather than the USDA plant hardiness zones.

CLICK ON THE MAP TO ENLARGE AND SEE ZONE DESCRIPTIONS

Homepage