USDA Hardiness Zones
What each zone means, and which growing region actually carries your calendar.
A zone is a winter survival number. It tells you what lives through your winter. It does not tell you when to sow, how long your season is, or how hard your summer bites. For sowing dates use the frost dates table.
| Zone | Winter low | Regions |
|---|---|---|
| Zone 3a | -40 to -35 F | Upper Midwest & Northern Plains, Alaska |
| Zone 3b | -35 to -30 F | Upper Midwest & Northern Plains, Alaska |
| Zone 4a | -30 to -25 F | Upper Midwest & Northern Plains, Mountain West, Alaska |
| Zone 4b | -25 to -20 F | Upper Midwest & Northern Plains, Mountain West, Alaska |
| Zone 5a | -20 to -15 F | Northeast & New England, Mountain West, Alaska |
| Zone 5b | -15 to -10 F | Northeast & New England, Midwest & Great Lakes, Mountain West, Alaska |
| Zone 6a | -10 to -5 F | Northeast & New England, Midwest & Great Lakes, Mountain West, Southern Plains |
| Zone 6b | -5 to 0 F | Northeast & New England, Mid-Atlantic, Midwest & Great Lakes, Mountain West, Southern Plains |
| Zone 7a | 0 to 5 F | Northeast & New England, Mid-Atlantic, Southern Plains |
| Zone 7b | 5 to 10 F | Mid-South, Northeast & New England, Mid-Atlantic, Southern Plains |
| Zone 8a | 10 to 15 F | Texas, Mid-South |
| Zone 8b | 15 to 20 F | North Florida, Gulf South, Texas, Pacific Northwest |
| Zone 9a | 20 to 25 F | North Florida, Gulf South, Pacific Northwest, Northern California & Central Valley |
| Zone 9b | 25 to 30 F | Central Florida, Desert Southwest, Southern California, Northern California & Central Valley |
| Zone 10a | 30 to 35 F | Central Florida, Desert Southwest, Southern California |
| Zone 10b | 35 to 40 F | South Florida, Southern California |
| Zone 11a | 40 to 45 F | South Florida, Southern California |
| Zone 11b | 45 to 50 F | South Florida, Southern California |