Plant hardiness zones have been adjusted by the USDA and Casper, Wyoming is moving up.

Horticulturalist, Donna Cuin, at the U-W Agricultural Extension office in Casper says the new map has moved us from a 4-b to 5-a. That means we've been upgraded from a low of 25 below zero to 20 below- subtle but apparently enough to make a difference.

"So, all of us in Casper who've been wanting to try some plants that are hardy in zone five are free to do so and hope that they can survive the conditions that we have here."

Cuin suggests if you try out a less hardy plant, choose a warm protected area to start with, especially somewhere shielded  from our coldest winds.

This is the first update to the plant hardiness map by the U.S. Department of Agriculture since 1990. The new hardiness maps are downloadable and free of charge.

Here's a link to the plant hardiness map produced by the USDA,

To read more about the Map and other new features, visit the USDA Newsroom to read the full release.