Climate Change: Should we be planting for warmer zones?

I'm in Zone 8, in Athens, GA. When we lived in Athens twenty years ago, it was Zone 7. I'm in the process of planting perennial trees and shrubs. Should I be looking to plant perennials for a warmer hardiness zone in anticipation of a warming world? I'm especially concerned about not planting things like apples that require certain chill hours that we now have but may not have in the not-too-distant future.

What are you doing? Any advice?

the climate could change in either direction.... solar minimum

yes try to zone push!

Yeah, but I would think about it in a couple ways. One thing I'm doing on my wild homestead is to locate the cooler micro-climates or at least more moderate micro-climates. I'm not in a rush to get this going but I'm planning on making some garden beds in these cooler areas so I can make sure I can still get good harvests on cool weather crops like spinach even in a warmer future.

I'm also in zone 8 so I also look at the plants that zone 8 is the coldest they can handle. I figure if I plant those plants then as things warm they should be fine. Right now the prediction for my area is that by 2085 our annual temperatures will be about the same as Sacramento, CA--I'm up in Olympia, WA right now. So that would be 1 zone higher than I'm in right now.

This also means I tend to avoid plants that the warmest they like is zone 8. I will grow them if they're short lived but I would not make them my long term foundation plants.

But going back to cooling things off... this is a big reason why I use mulch and woody debris (logs) around my plants. Both are great at cooling the soil and preventing the loss of moisture from evaporation. Rock piles work well too for this.

Even if the temperature is high if I can keep the soil cool and moist then the plants will handle it better.

But a forestry conference I recently went to about adapting to climate change made a really good point. It's not the increase in averages that will cause the biggest shifts in what grows where. Instead it's the big droughts, floods, etc. the big shocks that really shift things. While these shocks will come and go they can also result in a big loss of plants. When you look at trees that can live for 100+ years then even shocks that only show up every 10 years or so can make it really challenging to get those trees established.

So my takeaway is anything I can do to moderate the extremes will make the biggest difference. But I'm also looking at plants that are fine in zone 8 but don't mind zone 9 or 10. And I'm looking for the cool micro-climates on my property so I can fully utilize them too.

Hope that helps!

Climate change has effects that can be counterintuitive.  Where I live, jet pattern changes are resulting in more frequent and extreme visits from the Polar Express -- a jet stream full of arctic air from northern Canada.  So, yeah, I'm planting plants that need to be able to survive the overall warmer weather, but they also need to be able to withstand more severe winter cold events even than the native plants that are already here.  All we really know about the future is that it's going to be more chaotic as extra heat in the system powers more energetic weather patterns and events.  So it's not so much zone-shifting for me, as it is focusing on especially-hardy plants.  Plus I just do a lot of scattershot plantings, on the notion that I don't need to predict what will happen or what will survive it if I have thrown enough things at the wall for something to stick.  

To add to my last comment... some of the plants I'm exploring that are technically out of my climate zone are various citrus plants, bananas, avocados, and moringas. The ones I'm looking at all grow in zone 9 or higher. I think with the right micro-climate I could grow some of these right now--it's fully possible to create micro-climates that are a zone higher than the rest of your land.

In some cases I'm thinking about getting a bunch of seed (moringas) from a source that is as cool as I can find and then see if the new plants survive my winters in a warm micro-climate. Most won't but if some do then I could get these plants established now and they should still do fine in a warmer future.

This way I can get an early jump on these warm loving plants so I can have my own source of seeds/cuttings/etc. for future propagation.

Dan Boone wrote:Climate change has effects that can be counterintuitive.  Where I live, jet pattern changes are resulting in more frequent and extreme visits from the Polar Express -- a jet stream full of arctic air from northern Canada.  So, yeah, I'm planting plants that need to be able to survive the overall warmer weather, but they also need to be able to withstand more severe winter cold events even than the native plants that are already here.  All we really know about the future is that it's going to be more chaotic as extra heat in the system powers more energetic weather patterns and events.  So it's not so much zone-shifting for me, as it is focusing on especially-hardy plants.  Plus I just do a lot of scattershot plantings, on the notion that I don't need to predict what will happen or what will survive it if I have thrown enough things at the wall for something to stick.  

Very good point--being near the coast tends to protect my area from those cold blasts but anyone living in the interior would need to watch out for those. That does make it hard since you basically have both extremes to deal with...

My area is supposed to be drier and hotter in the summer but then our winters are supposed to be about the same but a bit warmer with more of the rain coming in big storms instead of being spread out in a bunch of smaller storms. I'm trying to slow the water down as much as possible so my land can deal with these large rain events to soak in the water so my land can handle the drier summers.

Daron Williams wrote:My area is supposed to be drier and hotter in the summer but then our winters are supposed to be about the same but a bit warmer with more of the rain coming in big storms instead of being spread out in a bunch of smaller storms. I'm trying to slow the water down as much as possible so my land can deal with these large rain events to soak in the water so my land can handle the drier summers.

The long term prediction for this part of the country is dryer and hotter overall, with many more extended summer droughts than formerly.  But what I'm seeing -- and what I'm not sure the models are tuned to predict -- is that we're getting more rain events year around that are tied to storm activity coming up out of the Gulf.  Big events like you say, and relatively rare (up to a few times a year) but still bringing a lot of water overall from a source that might have fired only once in five years in the past.  

But yeah -- in the long run most places, it's gonna be about avoiding damage during extreme weather events while catching and storing enough water to maintain food production during the heat and droughts.  

I would add that genetic diversity (biggest gene pool you can manage) is really important and that closely related species that can hybridize can be a serious gift to the future.  I try to grow seedlings from seeds obtained from distant sources with the hope that it will provide for resilience.  

Greg Martin wrote:I would add that genetic diversity (biggest gene pool you can manage) is really important and that closely related species that can hybridize can be a serious gift to the future.  I try to grow seedlings from seeds obtained from distant sources with the hope that it will provide for resilience.  

Likewise.  Plus, it's always possible your spot turns out to be the oasis in which those genes survive some current-times extinction bottleneck, and thus survive into the deep future.  It's not likely, but it's the best legacy any of us could hope for, IMO.  

Daron Williams wrote:
But a forestry conference I recently went to about adapting to climate change made a really good point. It's not the increase in averages that will cause the biggest shifts in what grows where. Instead it's the big droughts, floods, etc. the big shocks that really shift things.

All very good points, Daron, but this one especially I hadn't thought of. Like you, I'm piling up lots of logs, leaves, and wood chips...was thinking of making good soil but not that it would help cool the soil. Thanks for the reminder!

Dan Boone wrote:So it's not so much zone-shifting for me, as it is focusing on especially-hardy plants.  Plus I just do a lot of scattershot plantings, on the notion that I don't need to predict what will happen or what will survive it if I have thrown enough things at the wall for something to stick.  

Good point!

Dan Boone wrote:  Plus I just do a lot of scattershot plantings, on the notion that I don't need to predict what will happen or what will survive it if I have thrown enough things at the wall for something to stick.  

That sounds like a good plan.
Here in my part of the world we are having records of medium temperature and especially hot summers, combined with too low rainfalls.
In some parts of Germany the forests are dying (because of drought and parasite pressure); in some others parts, winegrowing is done as far north as never before. Some orchard farmers are getting fruit trees they would not have ventured to plant one or two decades ago (like peaches).

Winters are milder with less snow - a problem for beekeepers like me because the queen does hardly or not quit laying eggs at all (makes varroa management tricky).

Simply planning for a different zone is difficult for me:
We still can have frosts until mid May.
The seasons are still the same length, even if temperatures rise: I will not be able to harvest ripe peppers or eggplants even if they thrive in the summer months.
But then we will have autumn with short days and probably early frosts. Those might not be as long or frequent as in earlier times, but still one frost night will kill your plants.

Another problem I am facing as a suburban gardener with a really small garden:
Even with hotter summers I will still have a lot of shadow due to my latitude (comparable to the border between Montana and Calgary), and houses are built within a few meters distance.

many fruit and nut trees have chill requirements, you bring up good topic in our changing world