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Acknowledgments & Citation

BlueberriesThe USDA Agricultural Research Service thanks all of the many people who helped produce the newest edition of the USDA Plant Hardiness Zone Map (PHZM), especially the members of the PHZM Technical Review Team.

Special thanks are due to the director and staff of the PRISM Climate Group, Oregon State University, Corvallis, OR, for their tireless and generous services in the creation of the new map.

Suggested Citation

Please use the following reference when citing the Plant Hardiness Zone Map (PHZM) on this web site:

USDA Plant Hardiness Zone Map, 2012. Agricultural Research Service, U.S. Department of Agriculture. Accessed from