International Aroid Society

Zone Map of Western USA
Zone 1 Below -45°C
Below -50°F
Zone 7 -18°C/-12°C
0°F/+10°F
Zone 2 -45°C/-40°C
-50°F/-40°F
Zone 8 -12°C/-7°C
+10°F/+20°F
Zone 3 -40°C/-34°C
-40°F/-30°F
Zone 9 -7°C/-1°C
+20°F/+30°F
Zone 4 -34°C/-29°C
-30°F/-20°F
Zone 10 -1°C/+4°C
+30°F/+40°F
Zone 5 -29°C/-23°C
-20°F/-10°F
Zone 11 Above +4°C
Above +40°F
Zone 6 -23°C/-18°C
-10°F/0°F