Plant Hardiness Zones

Increase your gardening success by selecting plants suited to your cold hardiness zone and other environmental conditions.

Hardiness zones reflect the average minimum temperatures for an area. Buying cold hardy plants helps reduce losses when extreme winter temperatures occur.

You’ll find the USDA Plant Hardiness Map printed in garden books and catalogues. Locate your town on the map and match the color of your region on the map key. Or enter your zip code at the USDA Plant Hardiness Map website and your hardiness zone and minimum winter temperature range will appear.

Each hardiness zone represents areas within a 10-degree Fahrenheit range of minimum temperatures. This zone is subdivided into 5 degrees segments to more precisely represent that area within each zone.  The lower the number; the colder the winter temperatures.

A bit more information: Heat hardiness zones reflect the average number of days over 86 degrees (“heat days”) in a region. Plants are rated based on their ability to withstand a certain number of heat days. See the AHS Plant Heat Zone Map to find your heat zone to help you select plants suited to your area.