Growing zones, or hardiness zones, are determined by the average coldest temperatures in your area.
For US based farms, determining your growing zone is easy. Simply enter your zip code into the USDA's Plant Hardiness Zone Map.
International users may approximate their growing zone by estimating their region's average annual extreme minimum temperature:
Zone | From | To |
1a | −60 °F (−51.1 °C) | −55 °F (−48.3 °C) |
1b | −55 °F (−48.3 °C) | −50 °F (−45.6 °C) |
2a | −50 °F (−45.6 °C) | −45 °F (−42.8 °C) |
2b | −45 °F (−42.8 °C) | −40 °F (−40 °C) |
3a | −40 °F (−40 °C) | −35 °F (−37.2 °C) |
3b | −35 °F (−37.2 °C) | −30 °F (−34.4 °C) |
4a | −30 °F (−34.4 °C) | −25 °F (−31.7 °C) |
4b | −25 °F (−31.7 °C) | −20 °F (−28.9 °C) |
5a | −20 °F (−28.9 °C) | −15 °F (−26.1 °C) |
5b | −15 °F (−26.1 °C) | −10 °F (−23.3 °C) |
6a | −10 °F (−23.3 °C) | −5 °F (−20.6 °C) |
6b | −5 °F (−20.6 °C) | 0 °F (−17.8 °C) |
7a | 0 °F (−17.8 °C) | 5 °F (−15 °C) |
7b | 5 °F (−15 °C) | 10 °F (−12.2 °C) |
8a | 10 °F (−12.2 °C) | 15 °F (−9.4 °C) |
8b | 15 °F (−9.4 °C) | 20 °F (−6.7 °C) |
9a | 20 °F (−6.7 °C) | 25 °F (−3.9 °C) |
9b | 25 °F (−3.9 °C) | 30 °F (−1.1 °C) |
10a | 30 °F (−1.1 °C) | +35 °F (1.7 °C) |
10b | +35 °F (1.7 °C) | +40 °F (4.4 °C) |
11a | +40 °F (4.4 °C) | +45 °F (7.2 °C) |
11b | +45 °F (7.2 °C) | +50 °F (10 °C) |
12a | +50 °F (10 °C) | +55 °F (12.8 °C) |
12b | +55 °F (12.8 °C) | 60 °F (15.6 °C) |