Plant Hardiness Zones

Map and textual data provided courtesy of the U.S. National Arboretum, Agricultural Research Service, U.S. Department of Agriculture, Washington, DC

This data will help you determine which trees, plants and flowers you are able to grow and will have the most suitable environment they require in your back yard garden no matter where you are located.

Zones 2-10 in the map have been subdivided into light- and dark-colored sections (a and b) that represent 5 F (2.8 C) differences within the 10 F (5.6 C) zone. The light color of each zone represents the colder section; the dark color, the warmer section. Zone 11 represents any area where the average annual minimum temperature is above 40 F (4.4 C).




USDA Hardiness Zones and Average Annual Minimum Temperature Range
Zone Fahrenheit Celsius Example Cities
1 Below -50 F Below -45.6 C Fairbanks, Alaska;   Resolute, Northwest Territories (Canada) 
2a -50 to -45 F -42.8 to -45.5 C Prudhoe Bay, Alaska;   Flin Flon, Manitoba (Canada) 
2b -45 to -40 F -40.0 to -42.7 C Unalakleet, Alaska;   Pinecreek, Minnesota 
3a -40 to -35 F -37.3 to -39.9 C International Falls, Minnesota;   St. Michael, Alaska
3b -35 to -30 F -34.5 to -37.2 C Tomahawk, Wisconsin;   Sidney, Montana
4a -30 to -25 F
-31.7 to -34.4 C
Minneapolis/St.Paul, Minnesota;   Lewistown, Montana
4b -25 to -20 F -28.9 to -31.6 C Northwood, Iowa; Nebraska
5a -20 to -15 F -26.2 to -28.8 C Des Moines, Iowa;   Illinois
5b -15 to -10 F -23.4 to -26.1 C Columbia, Missouri;   Mansfield, Pennsylvania
6a -10 to -5 F -20.6 to -23.3 C St. Louis, Missouri; Lebanon, Pennsylvania
6b -5 to 0 F -17.8 to -20.5 C McMinnville, Tennessee;   Branson, Missouri 
7a 0 to 5 F -15.0 to -17.7 C Oklahoma City, Oklahoma;   South Boston, Virginia
7b 5 to 10 F -12.3 to -14.9 C Little Rock, Arkansas;   Griffin, Georgia
8a  10 to 15 F -9.5 to -12.2 C Tifton, Georgia; Dallas, Texas
8b 15 to 20 F -6.7 to -9.4 C Austin, Texas;   Gainesville, Florida
9a 20 to 25 F -3.9 to -6.6 C Houston, Texas;   St. Augustine, Florida
9b 25 to 30 F -1.2 to -3.8 C Brownsville, Texas;   Fort Pierce, Florida
10a 30 to 35 F 1.6 to -1.1 C Naples, Florida;   Victorville, California
10b 35 to 40 F 4.4 to 1.7 C Miami, Florida;   Coral Gables, Florida
11 above 40 F above 4.5 C Honolulu, Hawaii;   Mazatlan, Mexico

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