Hardiness Zones
To obtain the Hardiness Zone of a region it is necessary to record the absolute minimal
yearly temperature over several years. The number of the Zone is given by the average of
those temperatures according to the following table (Celsius/Fahrenheit converter):
| Fahrenheit |
Zone |
Celsius |
| Below -50 |
1 |
Below -45.6 |
| -50 | to | -40 |
2 |
-45.6 | to | -40.0 |
| -40 | to | -30 |
3 |
-40.0 | to | -34.4 |
| -30 | to | -20 |
4 |
-34.4 | to | -28.9 |
| -20 | to | -10 |
5 |
-28.9 | to | -23.3 |
| -10 | to | 0 |
6 |
-23.3 | to | -17.8 |
| 0 | to | 10 |
7 |
-17.8 | to | -12.2 |
| 10 | to | 20 |
8 |
-12.2 | to | -6.7 |
| 20 | to | 30 |
9 |
-6.7 | to | -1.1 |
| 30 | to | 40 |
10 |
-1.1 | to | 4.4 |
| Above 40 |
11 |
Above 4.4 |
The temperature is one limiting factor among several others such as humidity, soil
conditions, insolation, exposure to wind.
