Plant Hardiness Zone Map (2012)
The US National Arboretum (USDA) plant hardiness zone map. This is the new Internet version (January 2012) of the map that allows users to view individual states and also enter a zipcode to find your zone.
http://www.ars.usda.gov/main/main.htm
Plant Hardiness Zone Map (2012)
Species Selection, Biology (tree)
National