Of course I’m not taking into account the warming fantasy.
I really don’t care what anyone predicts about future temperatures, whether they are supposed to be cooler or warmer. They can’t accurately predict what temperatures will be next week. The idea that they know what will happen in 10 years is pure fantasy.
As for warming, I live in zone 6 and over the last 3 winters we have had zone 5 lows on 3 or 4 nights in two different years. We have also had record early freezes and record late freezes.
So here, the current trend is cooling. And that’s true of much of the Midwest down into Texas over the last 3 years.
As for chill hours, there is little in the plant world that is less precise than the need for chill hours. Chill hours are at best a guestimation, and even if they were scientifically accurate, they can vary greatly within nearby microclimates.
Yeah, it’s funny how people will refer to a USDA zone as though it’s an actual place, or at least something that is roughly equivalent across a gradient. The fact that Savannah, Georgia and Seattle, WA are in the same USDA zone is a pretty good illustration of its limited utility.
Don’t forget for those in coastal regions, it’ll be hard to garden and grow trees under water if it comes to pass that sea levels increase significantly. Maybe take up aquaculture? Growingfruitofthesea.org?
The extreme sudden temperature swings have been bad lately, and sure are troublesome for fruit trees. I don’t like them. One positive, however, might be extended growing season days for the vegetable garden. For us, it might be the difference between 85-90 growing days and 100-110. We used to wait til June 1st to plant. Seems like mid-May is a decent gamble lately. At least for a few plants. If they don’t make it, you can always throw some more in.
Tsunamis and hurricanes might concern me if I lived near the ocean.
But, a quarter inch sea level rise ever decade isn’t going to hurt any agriculture in Florida or any other place…not in our lifefimes. (And there’s only speculation that this rate of rise might increase…there aren’t any facts to support the speculation.)
I’d be a buyer of coastal property if no tsunamis or hurricanes could be promised.
A quick warning: the Wapo website doesn’t have some zones right. It gets mine wrong. The USDA has a strip of zone 6 running down the Shenandoah Valley in the ridge and valley parts. I think the wapo map isn’t quite finely partitioned enough to show it. I am very definitely not in zone 7.
I’m in a funny stretch - so this might be a problem particular to me. It IS a narrow stretch. Just 5 miles west and it’s 6a. Just 10 miles north and its 7. The USDA says I’m in a small strip of 6b. And I might even be more 6a because I’m on a particularly high hill. I know that @Rosdonald is in my strip and might be more cold also, because of the valley and she’s in a low spot. However, I drive to my work 10 miles away (which is zone 7a) and the plants are 1-2 weeks ahead of me! Even my neighbor 1.5 miles down the road has weeds popping up that I don’t.
I will say my parents recently had a tree expert out at their place (in MD). They have been in their house 40 years but the last 10 have had increasingly severe storms with trees coming down on their neighbor’s houses. Partly, this is because an environmental engineer warned many years ago that building in that area with large trees and very high rock shelf would be problematic. But also it seems that extreme storms are more frequent.
The tree expert recommend they remove a 120’ tulip popular because of the potential that one of these events could knock it down (it was not heathy internally, though it looked well externally). And cause major damage to their house. I think they would have not worried, except for what seems like increasing numbers of extreme weather events.
I have trees known to survive down to zone 2 and apple varieties that keep on trucking with overnight lows hitting 25f, but one thing I’m keenly keeping an eye out for is what the new weather conditions mean for insect pressure and disease.
I agree that the Wapo map is somewhat off. It pays to understand what your local climate zone actually is. We went from 6A-ish to 7A-ish already in the last 20 years, but there is quite a bit of difference locally due to elevation changes and water. I go more by Sunset zones than USDA zones. Either way, I expect more heat and variability is going to be the problem for me. I don’t expect that chill hours will be too different, and all the calculations keep USDA zones the same where it would make a difference to me- across lower Pennsylvania, Maryland and upper Virginia. I plant assuming colder than I expect at points in winter and hotter than I want in summer. Hoping zone pushing colder area bushes can be ok for under semi-permanent shade cloth, trees I expect more southern varieties will work. Humidity kills everything anyway around here.
As someone with a meteorology degree, I’d like to make the not-always-obvious point that weather and climate are two different things. The weather at any particular moment does not prove nor disprove climate change. So often in the media we see bias with extreme weather events being tied to climate change. The planet has always had extreme weather. I don’t believe that is changing. It’s the means that we’re worried about.
I think the planet (as a whole) has definitely warmed over the last 30 year normal period, but the debate is how much of that is anthropogenic. CO2 is an abundant tropospheric greenhouse gas and we know that’s been climbing steadily for quite awhile based on the Mauna Loa keeling curve. We’ve seen arctic sea ice areal extent and volume steadily decrease over the last couple of decades. We’ve seen permafrost lost in parts of the Canadian prairies. Despite changes in instrumentation over time and sometimes poor siting conditions at the official airport stations, the ice loss variables remain consistent.
Obviously the warmth is not necessarily even across the globe. Different regions have seen different extents of warming at different times of the year. As previously mentioned by another poster, the upper midwest has had some cooling. But overall across the globe, there’s definitely a warming trend. Will that reverse at some point? Maybe. The 60s-80s were a relatively cold period.
The brunt of the warming in the eastern US has been with the overnight mins. We’ve been cloudier, wetter, and more humid which limits the amount of radiational cooling possible at night. Areas further west that have seen more sustained drought periods may have some different climatic trends.
Whatever your stance on climate change is, I think we can all agree that cleaning up the planet, reducing emissions, and finding more renewable and efficient resources going forward is a positive. You won’t get growing zone predictions from me though.
The US Navy is purportedly doing some pretty intense strategic planning around the realities of an open and navigable Arctic Ocean.
There’s actually an interesting analog between weather/climate dichotomy and the effects of sea level rise. It’s hard to conceive of dynamic systems, so the tendency is to focus on individual data points or trends in a data set. Real dynamic systems behave in mind boggling ways, because their machinations are many and interrelated. In the case of sea level rise, many of the worst potential effects are due to the dynamics, namely tides. Water doesn’t just seek a level and stay there, it flows, and its dynamics reverberate through the whole system. My parents have a house in Ft. Myers, Florida, nearly 10 miles inland from the Gulf. During Hurricane Ian, they had nearly 3 ft. of storm surge in and around their house. Was it seawater pushed in from the wind, tidal water brought in by the normal functioning of the tides across the earth’s surface, rainwater from the 18 some inches of rain that fell directly on them, or flooding from the Calloosahatchee River jumping its banks. In a word, Yes.
It is worth reading and understanding the effect the sun has on our weather. Note in particular the “little ice age” roughly corresponding with the sun’s activity.
Ice sheet loss is the best indicator of sea level rise. Look at the readily available data on how much ice the earth has lost in the last 50 years. All current indicators are that nearly 90% of the current ice cover on earth will be gone within the next 80 years. That ice locks up enough water to cause sea level to rise over 3 feet worldwide. New Orleans is already below sea level. Guess what it will look like with daily tides going 3 feet higher than today.
It will also be difficult to garden and grow trees in the Pacific Northwest if Mt Ranier erupts.
The difference between a Ranier eruption and the sea levels increasing significantly is that it is an absolute certainty that Ranier will eventually erupt, while it is merely a fantasy that sea levels will rise enough to disrupt anything.
It says the same thing for Seattle (that it was 9a then 8b), but I made my own chart using the data direct from NOAA and it looks very different. I feel like maybe wapo did a bad job visualizing the data accurately. Here’s mine for Seattle based on data from 1948 to end of 2022, with the 30-year average starting in 1977. You can see it’s almost 8a (i.e. cold 8b) at the beginning, crossed to 9a in 2013:
looking at all the numbers is maddening. of course, the IPCC science says we will all be about 1 to 2C warmer within ten years. that’s a shift in lowest temps but-
more importantly, the seasons and the weather are becoming less predictable. with more energy (warmth) in the atmosphere and oceans, in the water cycle, it’s going to be harder to find things that survive. late cold snaps, early freezes, heat waves and drought/flood cycles are getting more common. so relying on the usual seasonal knowledge is getting riskier. they call it “weather weirding” and I know we’ve all seen it in some way, it’s not going to calm and go back to normal for any extended period now. just how we’ve decided to manage the climate and I don’t like to discuss possible solutions to it, that’s the political part.
I plant for the zone, but I consider our local weirdness and climate more than that, even.
This sounds really familiar. Here in South Texas our Summers are brutal and our Winters are the variable. It can be 80° in October and a few days later we have frost. Really bad Winters put us in the teens for multiple days.Very tough on trees. I know all I can do is try to keep them healthy and mineralized and give some protection to the subtropicals. I have trees/plants with varying cold tolerance and requirements so that I have some production regardless of weather conditions.
Negative double digit temperatures like some of you deal with would have me running South as soon as the roads were passable. D
There’s a really interesting brand of seaweed kimchi (“sea-chi”) in a region that was based on lobster fishing that then was no longer able to support folks - they planted seaweed, and it’s become big business.
