The zones are a changin.... new USDA maps updated from the last (2012).
https://phys.org/news/2023-11-hardiness ... imate.html

Edited my signature to reflect the change. Was right on the line of 9a and b, now solidly in 9b.

Yeah, I went from 6b to 7a, I don't know how much difference that really makes, since I'm about 10 miles from the edge of 6b now, probably before I was 10 miles from the edge of 7a.

It makes no difference to me because we still get killer freezing temperatures all the time.

12a, wooooo! Doesn’t mean anything to me though…

Still the same for me

worth1 wrote: ↑Sun Nov 19, 2023 5:21 pm It makes no difference to me because we still get killer freezing temperatures all the time.

Bastrop is now zone 9a. According to USDA, killer hard freezes sub 25°are a thing of the past!

Galveston Island, Bolivar, Smith Point, part of Corpus Christi, Rockport and the Louisiana Mississippi delta area are now 10a. Tropical Texas is expanding!

karstopography wrote: ↑Sun Nov 19, 2023 10:29 pm

worth1 wrote: ↑Sun Nov 19, 2023 5:21 pm It makes no difference to me because we still get killer freezing temperatures all the time.

Bastrop is now zone 9a. According to USDA, killer hard freezes sub 25°are a thing of the past!

I don't believe it.
We'll get more killer freezes in the future like we had.
This 9A thing has been going on for a while now.

Thanks for posting that. We were officially in 8a before and now 8b. But there have always been winters that were slightly 7b-ish so moving to 8b doesn't really mean a thing to me. The summers have always been hot, some years more wet or dry than others, winters milder or worse. Mother Nature does what she wants regardless of maps.

Won't be starting an avocado orchard anytime soon.
I've had some winters that volunteer tomato plants grew and produced fruit with no protection.
The next winter it got to 10 degrees.

I don't know the details of how these hardiness map boundaries are calculated, but it sounds like the warmer seasons overall are pushing up an 'average' temperature to define the zone, but not accounting for those polar vortex events which are certainly fresh enough in our memories, and could happen again any time.
I don't think the hardiness maps are designed to reflect those weather extremes which aren't part of a "normal" season. Even though the displacement of polar air far to the south is part of the pattern connected to high rates of warming in the far north.
Then again, microclimate makes a big difference too. There are always settings where the extremes are either dampened or pushed.

Now 6B instead of 6A. Will be interested in seeing if it makes any difference. In the past have lost Zone 6 plants due to a harsh winter of freezing and thawing. May try a couple of those same plants again as a test. There are some euphorbia varieties I really love but didn’t survive more than a couple of winters. We’ll see how El Niño treats us in NE Pa this winter! Snow is a good thing to protect plants but not the back!

There appears to be a little 5A dot in 5B south-central WESconsin; might the 77 Square Miles Surrounded By A Sea Of Reality.

The Gotch

The new map has me in Zone 9B now instead of 9A. The microclimate I’m in along the St. John’s river is definitely warmer than the rest of North Florida.