USDA Says Oklahoma's Planting Zone Map Is Getting Warmer

The federal government's official map of colorful planting zones has been updated for the first time since 1990.

The U.S. Department of Agriculture guide for gardeners reflects a new reality: The coldest day of the year isn't as cold as it used to be.

The USDA says so some plants that once seemed too vulnerable to the cold now survive further north.

There are changes to 5 of the 13 planting zones that will impact Oklahoma.

According to the USDA, the extreme minimum ranges from -10 degrees in the western tip of the Oklahoma panhandle to 10 degrees above zero in far southeastern Oklahoma.

The USDA says the new map uses data measured at weather stations during the 30-year period 1976-2005.

To view the new map, http://planthardiness.ars.usda.gov/PHZMWeb/.