We call where you are up north. It is also elevation and proximity to the ocean. We are on a sand ridge before you get into the piedmont. We are in a transition zone of sorts. The old coast line.No I'm in the valley. We rarely see snow and get below 20 an average of about 6 nights a year. It's very rate to have a day that is not above freezing. Good ole Southeastern heat and humidity. And way too much rain the last few years, but with drought problems all over the rest of the country I hate to complain about the rain.
Just east of us the elevation has a gradual drop to sea level. The elevation climbs steadily going west. It is a bit different between here and there. Our summers are dominated by Bermuda Highs that do not go that far west. If you want to see an illustration, look at a range map of the Alligator and some other things that would not survive Tennessee winters. We cannot grow the same plants varieties (often) that we would from the sandhills to the lowcountry. It changes fast. Georgia is like that to. There is a big difference in chill hours from west to east. It is more than double.
I am not trying to debate, just trying to illustrate the differences. There is a big difference between here and our coast because of the ocean. As we drop in elevation and head to the ocean there is a decent difference in just 120 miles. It changes fast. Faster than we would think looking at a map. I will put it this way, in that 100 miles, there is near a month of growing season difference.
I have often said that I should move 100 miles north or south. Being in the transition zone has some plant growing challenges. The advantage is that done just right, we have a large variety of things we can grow.