What is a plant hardiness zone?

A plant hardiness zone is a geographic area defined by its average annual extreme minimum temperature. The USDA Hardiness Zone Map divides North America into 13 zones (1a to 13b), each representing a 5°F temperature range. Knowing your zone helps you choose plants that can survive your winters.

How do I find my USDA hardiness zone?

Enter your 5-digit zip code in the zone finder above. The tool will instantly show your USDA hardiness zone, the temperature range, and plants that thrive in your area.

What is the difference between USDA and Canadian hardiness zones?

USDA zones are based solely on average annual extreme minimum temperature. Canadian zones (from Natural Resources Canada) use 7 climatic variables including minimum temperature, frost-free period, summer rainfall, and snow cover. The two systems are NOT equivalent — a Canadian Zone 6 is not the same as USDA Zone 6.

Can I grow plants rated for warmer zones?

Plants rated for warmer zones may survive in protected microclimates, with mulching, or as annuals. Conversely, plants rated for colder zones will generally thrive in your area since they can handle even lower temperatures than you typically experience.

Does the hardiness zone account for summer heat?

No. USDA hardiness zones only measure winter cold tolerance. For heat tolerance, look at the AHS (American Horticultural Society) Heat Zone Map, which measures the number of days above 86°F (30°C).

Plant Reference

Tools & Calculators

Zone Finder

Hardiness Zone Finder

Enter your zip code or postal code to find your USDA or Canadian plant hardiness zone. USDA results include catalogue matches; Canadian results stay within the distinct NRCan system.

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