The USDA Plant Hardiness Zone system divides the US into 13 zones based on average annual minimum winter temperatures. Knowing your hardiness zone tells you which perennial plants, trees, and shrubs will reliably survive your winters. Select your state to find your general zone range.
Find Your Hardiness Zone
USDA Hardiness Zone Temperature Reference
| Zone | Min Temp (°F) | Min Temp (°C) | Typical Regions |
|---|
How to Use USDA Hardiness Zones for Planting
The USDA Plant Hardiness Zone lookup helps you select plants that will survive your climate. Every perennial plant, tree, and shrub sold in the US is labeled with a zone range. If your zone is within that range, the plant is cold-hardy for your winters.
Reading Plant Zone Labels
A plant labeled "Hardy in zones 5-9" can survive minimum winter temperatures down to -20°F (zone 5) and won't suffer heat stress up to zone 9 conditions. If you're in zone 7, that plant will thrive. A plant labeled "Zone 9-11" will not survive a zone 7 winter and needs to be treated as an annual or container plant brought indoors.
Microclimates Matter
Your property likely has multiple microclimates. South-facing walls can be 1-2 zones warmer. Low spots collect frost (colder). Urban areas retain heat (warmer). Use these to your advantage — plant tender shrubs against a south-facing wall for extra protection, or reserve frost pockets for cold-hardy plants.
FAQ
Is this USDA hardiness zone lookup free?
Yes, completely free with no signup required. Find your plant hardiness zone by selecting your state.
What is the USDA Plant Hardiness Zone?
The USDA Plant Hardiness Zone Map divides the US into 13 zones based on average annual minimum winter temperature, in 10°F increments. Zone 1 is the coldest (Alaska interior, below -50°F) and Zone 13 is the warmest (parts of Hawaii and Puerto Rico, above 60°F). Most of the continental US falls in zones 3-10.
How do I use my hardiness zone?
When shopping for perennial plants, shrubs, or trees, check the plant tag for its hardiness zone range. If your zone is within that range, the plant should survive your winters. Zone 6a means average minimum temps of -10 to -5°F — plants rated 6a or lower will survive those temperatures.
What is the difference between zone 6a and 6b?
Each zone is divided into subzones 'a' and 'b' differing by 5°F. Zone 6a has average minimum temperatures of -10 to -5°F, while zone 6b is -5 to 0°F. The 'b' subzone is slightly warmer and can support plants that zone 6a cannot reliably overwinter.
Does climate change affect hardiness zones?
Yes. The USDA updated the map in 2023, and many areas shifted warmer by half a zone. Some previously zone 7 areas are now zone 7b or even zone 8a. Local microclimates (urban heat islands, proximity to water, elevation, slope) can make your garden warmer or cooler than the official zone.