Just weeks ago, the U.S. Department of Agriculture released a new, updated Plant Hardiness Zone Map. I was out of commission, away from my phone that afternoon, and boy, when I checked in, I had no less than four or five messages from colleagues, friends and even listeners making sure I was aware of this breaking development!

In case you didn’t know, this Plant Hardiness Zone Map (PHZM) is a reference for gardeners to decide which plant species will do best in their region. Recommended zones that a plant can survive are always listed on a plant’s tag (pictured).

Areas around the United States are broken up by ‘average annual extreme minimum winter temperature’, displayed as 10-degree F zones and are classified in differing “hardiness zones”. The higher the numbered zone (most of N. Georgia is now zone 8a instead of 7b), the warmer that average minimum winter temperature.

So what this new map reveals is that most of N. Georgia now sees an average minimum temperature of between 10 and 15 degrees F, warmer than the 5 to 10 degree F average when the map was last updated in 2012. I had to talk to some industry experts to see if we should now change up some desired plants in our landscapes!

Bodie Pennisi, Professor of Horticulture at UGA, says “while we may be tempted to plant more tropical plants, they may not dependably make it [in our area]. Plants themselves have not changed. It’s just that their chance of survival has increased.”

And Christie Bryant, owner of Speaking For the Trees, makes the point that “this change is reactionary, not predictive. There’s no reason to change anything. Just be aware, as we get warmer and warmer, we’re also going to have more extreme cold weather events. If you change a bunch of stuff, you’re going to end up messing up!”

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