New Plant Hardiness Zone Map

The Plant Hardiness Zone Map is used to indicate plant survival (winter hardiness) in an area. The United States Department of Agriculture recently released a new Plant Hardiness Zone Map. The last time the map was updated was 1990. New hardiness zones are based on the lowest yearly daily minimum temperature from 1976-2005 collected from almost 8000 weather stations in the US and bordering areas of Canada and Mexico. The new map is interactive. It allows for viewing the hardiness zones of an area at much finer scale than previously and also includes a feature where a zip code can be entered to view the hardiness zone of the area. The Plant Hardiness Zone Map can be found at http://planthardiness.ars.usda.gov.

Want more information? Try these sites:

http://planthardiness.ars.usda.gov/PHZMWeb/AboutWhatsNew.aspx

Daly, C., M.P. Widrlechner, M.D. Halbleib, J.I. Smith, and W.P. Gibson. 2012. Development of a new USDA Plant Hardiness Zone Map for the United States. Journal of Applied Meteorology and Climatology, 51: 242-264. http://journals.ametsoc.org/doi/full/10.1175/2010JAMC2536.1

Widrlechner, M.P., C. Daly, M. Keller, and K. Kaplan. 2012. Horticultural Applications of a Newly Revised USDA Plant Hardiness Zone Map. HortTechnology, 22: 6-19. http://horttech.ashspublications.org/content/22/1/6.abstract