Understanding USDA Plant Hardiness Zones
The USDA Plant Hardiness Zone Map helps gardeners determine which perennial plants are most likely to survive winter in their area. Each growing zone is based on the average annual extreme minimum winter temperature for that location.
The current 2023 USDA Plant Hardiness Zone Map uses weather data from 1991–2020. The country is divided into 10°F zones, with each zone further divided into 5°F half-zones labeled “a” and “b.”
Knowing your growing zone makes it easier to choose plants suited for your winters. It can also help you understand whether certain plants may grow as annuals or perennials in your area.
Why Your Growing Zone Matters
At Plant Addicts, we list the recommended growing zones for each plant whenever possible. Before ordering a perennial, shrub, tree, or other cold-hardy plant, compare your zone with the plant's recommended zone range.
Hardiness zones are a guide rather than a guarantee. Snow cover, wind exposure, elevation, nearby buildings, urban heat, and other microclimates can make one garden warmer or colder than another nearby.
How To Use Your Growing Zone
1. Find Your Zone
Use the ZIP code finder above to identify your USDA Plant Hardiness Zone.
2. Check The Plant
Look for the growing-zone range listed on each Plant Addicts product page.
3. Plan For Winter
Plants rated for your zone are better suited to withstand the typical winter cold in your area.
4. Consider Your Yard
Sun, soil, drainage, wind and protected areas can all influence how well a plant performs.
Average First & Last Frost Dates By Growing Zone
Frost dates are general estimates and are not what determines your USDA hardiness zone. Actual frost dates can vary considerably by location, elevation, weather patterns, and local microclimates.
| Growing Zone | Average Last Spring Frost | Average First Fall Frost |
|---|---|---|
| Zone 1 | May 22 – June 4 | August 25 – 31 |
| Zone 2 | May 15 – 22 | September 1 – 8 |
| Zone 3 | May 1 – 16 | September 8 – 15 |
| Zone 4 | April 24 – May 12 | September 21 – October 7 |
| Zone 5 | April 7 – 30 | October 13 – 21 |
| Zone 6 | April 1 – 21 | October 17 – 31 |
| Zone 7 | March 22 – April 3 | October 29 – November 15 |
| Zone 8 | March 13 – 28 | November 7 – 28 |
| Zone 9 | February 6 – 28 | November 25 – December 13 |
| Zones 10–13 | Often frost-free | Often frost-free |
USDA Growing Zone Temperature Guide
USDA zones are based on average annual extreme minimum winter temperatures. A higher zone number generally means a warmer winter climate.
-60°F to -50°F
-50°F to -40°F
-40°F to -30°F
-30°F to -20°F
Shop Zone 4 Plants → Zone 5
-20°F to -10°F
Shop Zone 5 Plants → Zone 6
-10°F to 0°F
Shop Zone 6 Plants → Zone 7
0°F to 10°F
Shop Zone 7 Plants → Zone 8
10°F to 20°F
Shop Zone 8 Plants → Zone 9
20°F to 30°F
Shop Zone 9 Plants → Zone 10
30°F to 40°F
Shop Zone 10 Plants →
40°F to 50°F
50°F to 60°F
60°F to 70°F
Each full zone is divided into an “a” and “b” half-zone representing 5°F temperature increments.
States By USDA Growing Zone
Most states contain more than one growing zone because winter temperatures vary by latitude, elevation and local geography. Use the ZIP code finder above for your specific location rather than relying on the state list alone.
Zone 1
Zone 2
Zone 3
Zone 4
Alaska, Arizona, Colorado, Idaho, Iowa, Maine, Michigan, Minnesota, Montana, Nebraska, Nevada, New Hampshire, New Mexico, New York, North Dakota, Oregon, Utah, Vermont, Washington, Wisconsin, Wyoming
Shop Zone 4 PlantsZone 5
Alaska, Arizona, California, Colorado, Connecticut, Idaho, Illinois, Indiana, Iowa, Kansas, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Mexico, New York, North Carolina, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming
Shop Zone 5 PlantsZone 6
Alaska, Arizona, California, Colorado, Connecticut, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Missouri, Montana, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wyoming
Shop Zone 6 PlantsZone 7
Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Georgia, Idaho, Illinois, Kansas, Kentucky, Maryland, Massachusetts, Mississippi, Missouri, Nevada, New Jersey, New Mexico, New York, North Carolina, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Virginia, Washington, West Virginia
Shop Zone 7 PlantsZone 8
Alabama, Alaska, Arizona, Arkansas, California, Florida, Georgia, Louisiana, Maryland, Mississippi, Nevada, New Mexico, North Carolina, Oklahoma, Oregon, South Carolina, Tennessee, Texas, Utah, Virginia, Washington
Shop Zone 8 PlantsZone 9
Alabama, Arizona, California, Florida, Georgia, Hawaii, Louisiana, Mississippi, Nevada, New Mexico, Oregon, South Carolina, Texas, Utah, Washington
Shop Zone 9 PlantsZone 10
Arizona, California, Florida, Hawaii, Louisiana, Nevada, Texas
Shop Zone 10 PlantsZone 11
Zone 12
Zone 13
Frequently Asked Questions
What is a plant hardiness zone?
What do "a" and "b" mean in plant hardiness zones?
Can I grow plants outside my hardiness zone?
Did my USDA growing zone change?
Does my hardiness zone tell me when to plant?
Do hardiness zones matter for container plants?
Sources
- U.S. Department of Agriculture Agricultural Research Service. 2023 USDA Plant Hardiness Zone Map. https://planthardiness.ars.usda.gov/
- PRISM Climate Group, Oregon State University. Climate mapping and temperature data used in development of the 2023 USDA Plant Hardiness Zone Map.
- National Oceanic and Atmospheric Administration, National Centers for Environmental Information. Historical freeze and frost-date climate data.
- Soil temperature and local climate data from external weather and climate data providers used by the Plant Addicts growing zone tool.