All 26 USDA Hardiness Zones

From Zone 1a (winter lows -60°F) to Zone 13b (60°F). Click any zone for the full planting calendar.

ZoneWinter LowSeason (days)Last FrostFirst Frost
10a 30°F – 35°F 340 days Mid to late January Late December / frost-free in most years
10b 35°F – 40°F 360 days Early January Frost-free in most years; occasional late December frosts
11a 40°F – 45°F 365 days Frost-free year-round Frost-free year-round
11b 45°F – 50°F 365 days No frost ever No frost ever
12a 50°F – 55°F 365 days No frost ever No frost ever
12b 55°F – 60°F 365 days No frost ever No frost ever
13a 60°F – 65°F 365 days No frost ever No frost ever
13b 65°F – 70°F 365 days No frost ever No frost ever
1a -60°F – -55°F 92 days Late May Late August / early September
1b -55°F – -50°F 105 days Mid-late May Early September
2a -55°F – -50°F 110 days Mid to late May Early September
2b -50°F – -45°F 120 days Early to mid May Early September
3a -40°F – -35°F 120 days Late April to mid May Late August to early September
3b -35°F – -30°F 130 days Late April to early May Mid September
4a -30°F – -25°F 138 days Late April to early May Mid September
4b -25°F – -20°F 145 days Mid to late April Late September
5a -20°F – -15°F 155 days Mid April to early May Late September to early October
5b -15°F – -10°F 165 days Late April Mid to late October
6a -10°F – -5°F 173 days Early to mid April Mid to late October
6b -5°F – 0°F 180 days Late March to mid April Late October to early November
7a 0°F – 5°F 195 days Mid to late March Late October to early November
7b 5°F – 10°F 205 days Mid March Mid November
8a 10°F – 15°F 230 days Late February to mid March Mid to late November
8b 15°F – 20°F 245 days Late February Late November
9a 20°F – 25°F 285 days Late January to mid February Mid to late December
9b 25°F – 30°F 305 days Mid January Late December / rare frost