Hardiness Zone
The hardiness category is indicated for each individual plant species. The hardiness zones are developed by the Department of Agriculture in the United States. For plants in pots, you need to reduce the zone by two points, as potted plants freeze quicker than plants growing in open ground.
|
USDA zone |
Minimum temperature (°C, average) |
Winter hardiness |
Example countries/ areas |
|
1 |
< -45,5 |
very extreme |
Central Siberia |
|
2 |
-45,5 to -40,1 |
extreme |
Siberia |
|
3 |
-40,0 to -34,5 |
very excellent |
Lapland |
|
4 |
-34,4 to 28,9 |
excellent |
Russia, Northern Scandinavia |
|
5a |
-28,9 to -26,1 |
very good (a) |
Belarus, Eastern Baltic States |
|
5b |
-26,0 to -23,4 |
very good (b) |
North-East Poland, Southern Ukraine, Central Sweden, Southern Finland |
|
6a |
-23,3 to -20,6 |
good (a) |
Eastern Poland, Slovakia, East and Central Southern Sweden, Southern Norway |
|
6b |
-20,5 to -17,8 |
good (b) |
Central Poland, Eastern Hungary, Czech Republic, South Sweden |
|
7a |
-17,7 to -15,0 |
reasonable (a) |
Eastern Germany, West Poland, East and West coast of Sweden |
|
7b |
-14,9 to -12,3 |
reasonable (b) |
Eastern Netherlands, South coast Sweden, Eastern Denmark |
|
8a |
-12,2 to -9,5 |
moderate (a) |
Central Netherlands, Belgium, Northern and Central France, Northern England |
|
8b |
-9,4 to -6,7 |
moderate (b) |
Dutch coast, Western France, Northern Italy, Central England |
|
9 |
-6,6 to -1,2 |
poor |
South coast of France, Central Italy, Central Portugal, South coast of England |
|
10 |
-1,1 to +4,4 |
very poor |
South and East coast of Italy, South coast of Spain, Southern Greece |
|
11 |
> +4,4 |
none |
(sub)tropical Africa |
Bron: Department of Agriculture, Verenigde Staten