United States Department of Agriculture

Plant Hardiness Zone Maps

(Click any map for a larger, full-sized version.)

2012 Plant Hardiness Zone Map

The 2012 USDA Plant Hardiness Zone Map is the standard by which gardeners and growers can determine which plants are most likely to thrive at a location. The map is based on the average annual minimum winter temperature, divided into 5F half-zones (above) or 10F full-zones. The 2012 USDA map uses data measured during 1976-2005. An interactive version of the map is available that allows one to select individual states (or half-states in the case of California and Texas), and detailed maps of different sizes are accessible. A large map showing only full-zones is also available.

 
   1990 Plant Hardiness Zone Map                  2006 Plant Hardiness Zone Map

There has been quite a change in the plant hardiness zones between 1990 and 2006. The zones have visibly shifted northward, a difference of one 5F half-zone warmer between the two maps. This is due to anthropogenic global warming. The 1990 map was based on data from 1974-1986. The 2006 map was based on data from 1986-2002; it was released by the Arbor Day Foundation in 2006 after the USDA pulled a 2003 map released by the American Horticulture Society. In 1990, Midland and Odessa were in Zone 7B, but since 2006 the two cities have been in Zone 8A. The 2012 USDA map, which is very similar to the 2006 map, confirms this warming trend.


2012 West Texas Plant Hardiness Zone Map

For the first time, individual state plant hardiness zone maps are available. Two states, California and Texas, are large enough that each state is divided into two maps. The new maps are remarkably detailed and will greatly help gardeners determine their plant hardiness zone. The individual state maps are available from the links above.


Texas Citizens for Science
Last updated: 2012 February 17