Nashville (AP) -- A national arbor group has updated the US Department of Agriculture's plant hardiness zone map.
The changes place most of Tennessee in a warmer category because of recent climate patterns.
The National Arbor Day Foundation used climate data that showed many areas have shown a warming trend since 1990, when the USDA last updated its plant hardiness zone map.
The maps divide the country into ten zones based on average low temperatures. The zones are used to identify what plants can survive at those average temperatures.
The National Arbor Day Foundation's new map places nearly all the state in zone seven, where plants such as camellias and cypress trees are acceptable to plant.
The 1990 USDA map places all of Middle Tennessee and parts of West and East Tennessee in zone six, a cooler zone where hardier plants have a better chance for survival.
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