USDA Plant Hardiness Zone Map
Looking for grow zones? This zones for planting plants guide shows your growing zone, frost dates, and best plants to grow.
Note: These USDA hardiness zones apply to outdoor garden plants (vegetables, fruits, herbs, and landscape plants). Indoor houseplants like pothos, snake plants, and monstera are not affected by outdoor winter zones and can be grown indoors in any climate.
| Zone | Min Temp (°F) | Last Frost | First Frost | Growing Season |
|---|---|---|---|---|
| 3a | -40 to -35 | May 15 - 31 | September 1 - 15 | ~90 days |
| 3b | -35 to -30 | May 1 - 15 | September 15 - 30 | ~105 days |
| 4a | -30 to -25 | May 1 - 15 | September 15 - 30 | ~120 days |
| 4b | -25 to -20 | April 25 - May 10 | October 1 - 15 | ~135 days |
| 5a | -20 to -15 | April 20 - May 5 | October 1 - 15 | ~150 days |
| 5b | -15 to -10 | April 15 - 30 | October 10 - 25 | ~165 days |
| 6a | -10 to -5 | April 10 - 25 | October 15 - 31 | ~180 days |
| 6b | -5 to 0 | April 5 - 20 | October 20 - November 5 | ~195 days |
| 7a | 0 to 5 | March 25 - April 10 | October 25 - November 10 | ~210 days |
| 7b | 5 to 10 | March 20 - April 5 | November 1 - 15 | ~225 days |
| 8a | 10 to 15 | March 15 - 30 | November 5 - 20 | ~240 days |
| 8b | 15 to 20 | March 10 - 25 | November 10 - 25 | ~255 days |
| 9a | 20 to 25 | February 25 - March 10 | November 20 - December 5 | ~270 days |
| 9b | 25 to 30 | February 20 - March 5 | November 25 - December 10 | ~285 days |
| 10a | 30 to 35 | February 15 - 28 | December 1 - 15 | ~300 days |
| 10b | 35 to 40 | February 10 - 22 | December 5 - 20 | ~315 days |
What Are USDA Plant Hardiness Zones?
The USDA Plant Hardiness Zone Map is the standard by which gardeners can determine which plants are most likely to thrive at a location. These grow zones, also known as zones for planting plants, are based on the average annual minimum winter temperature, divided into 10°F zones.
How Are Zones Divided?
Each zone is divided into "a" and "b" halves, representing 5°F increments. For example, Zone 7a has minimum temperatures of 0°F to 5°F, while Zone 7b has minimum temperatures of 5°F to 10°F.
What Can You Grow in Each Zone?
Zone 3a (coldest): Only the hardiest plants like kale, carrots, and winter onions. Zone 7b: Most vegetables and herbs grow well here, including tomatoes, peppers, and lavender. Zone 10b (warmest): Tropical plants like mango, banana, and citrus thrive year-round.
Data source: USDA 2023 Plant Hardiness Zone Map (PRISM Climate Group, Oregon State University). Frost date ranges are based on USDA Hardiness Zone Method.