temperature zones for gardening
The USDA Plant Hardiness Zone Map. Considered the standard measure of plant hardiness, the USDA Zone Map is generally is based on the average annual minimum winter temperature, divided into 10-degree F zones. Go to the USDA Plant Hardiness Zone Map! Click on above image and it will take you to the USDA Plant Hardiness Zone Map. Note: This USDA Plant Hardiness Zone Map was updated in January of 2012, the first update since 1990. About half of the country is a half-zone warmer.