I’m east Washington State. high elevation, high desert. not coastal at all and not in an area that sees desertification past where we are. last year we had drought, year before we had the heat dome.
it’s a really odd climate region to begin with. here our season is getting more abrupt and extreme between winter cold/summer heat, winter wet/summer dry.
it looks like you’re warming up and getting more humid all the time. the big storms out your way are pretty intense to begin with (SC, further south a bit though) and that’s also a concern.
does it feel less predictable, when you plant out, how crops fare? say the last five to ten years. here it does, where I grew up it’s changed a lot too. when I go back to visit a lot of the local favorite plants aren’t doing well, and there’s a lot of new things people are trying, to make up for it.
There is enough of a change in weather patterns that I am planning to grow olives, pomegranates, and oranges. I am already growing muscadines that are typically not recommended for this area. Side note, muscadines grow from Florida up into parts of Kentucky, but several commercial cultivars are limited to southern regions. An example is Granny Val which will winter kill much north of Florida.
Thought I’d throw in a few more charts showing why I’ve decided to try breeding cold-hardy avocados here in Seattle and the Cascadian lowlands. First, the classic USDA zone data (annual minimum) shown both in the 30-year average (as USDA uses), and also with 10-year and annual data, for those who rightfully don’t tend to trust long-term averages:
But as others have pointed out, zone shifting alone doesn’t really tell the full story. However, in some other key metrics, Seattle has become a lot more conducive to zone-pushing than it used to be. For example, if you look only at days at or below 25°F, you can see how many more of these “below zone 9b” days Seattle used to get, and how in recent years there have even been a number of years that don’t go below that at all, which was rare earlier in the dataset:
The last time Seattle had a year with more than 10 days at or below 25°F was 30 years ago! But at the start of the dataset, that was commonplace.
And finally, for something that’s fairly frost-tender like avocados, the total number of freezing days is worth noting, and that number has also dropped noticeably since the late 1940s, though less steeply in recent decades than earlier in the dataset:
Of course I’ve had the bad “luck” of two straight La Nina years for the first two years of this project, but even those were relatively mild compared to the type of temperatures a “cold” winter would deliver 40+ years ago around here, and I have some avocados surviving outdoors.
when I lived in Seattle and then in coastal central Oregon, from maybe 25 years ago up until 10 years ago. we would get snow, freezing days, for about two weeks each winter. I couldn’t keep figs alive! my old house in Oregon AND my old place in Seattle now have fig trees in the yard. both places, and not Chicago Hardy growing back but plants that are living through those winters.
it seems only a few days get truly cold there now.
I have been planting a lot of figs over the last year or so, and even the tiny rooted starts appear to have all survived the winter with varying degrees of damage to stems and dormant buds. I posted some photos here of varieties that seemed to make it through this winter (low of 17°F and generally colder than the new usual):
Wine industry professional here. And while I work in the viticulture side and not the winery, I do have a masters degree in winemaking.
Alan, you are correct. Soil that is high in nutrients with lots of available water can have a negative impact on wine quality, usually due to excessive vigor, but that really depends on the variety/rootstock, how you manage the vineyard, and the type of wine you’re making. What is good wine anyway? If it’s ratings you’re looking at, plenty of top-scoring wines have been made from vineyards on the Napa Valley floor where soils are rich and groundwater is never far away.
That same deep, fertile soil is great for dry farming, which isn’t possible on shallower soils. Dry farming doesn’t automatically translate to better quality wine, however. Until recently, most of the grapes for White Zinfandel were dry farmed. At my work, some of our best sites are dry farmed, but some of our worst quality sites are as well. Dry farming is one of those ideas that is nice in theory but not necessarily practical or “better” in actuality. Few vineyards in California can be fully dry-farmed, and drought years are always going to be problematic if you don’t have an irrigation system in place to make up for deficits in rainfall. I have numerous colleagues that weren’t able to make a 2021 vintage from some dry-farmed vineyards because yields were too low from the lack of rainfall.
To bring this back to the original topic, the last several years of drought, heatwaves, and general weather unpredictability have definitely negatively impacted the industry. Last year, the growing season was pretty ideal until early September, when we were hit with one of the longest stretches of consecutive days over 100 degrees ever. Overnight, vineyard blocks that were a few weeks away from ripening needed to get picked immediately, not that anyone had the labor to do so. Brix shot up from 23-24 to over 28. Many people were picking raisins, not grapes. The leaves on the south facing side of the rows fried in a lot of vineyards, further exposing the fruit to the sun.
In general, excessive heat only has negative impacts on wine quality. Hot days and warm nights cause anthocyanins to break down, resulting in wine with less color. Warm nights also cause acid levels to drop faster, which makes for flabby wines prone to microbial contamination. High temperatures make sugar levels rise faster than the tannin quality matures, giving you wine that is excessively high in alcohol while still having an underripe quality. More importantly, heatwaves reduce yield, whether that is due to sunburn and physical damage to the fruit, loss of fruit weight through dehydration, or contamination from wildfire smoke.
Regardless of how you feel about climate change, current conditions are unpredictable enough already that the industry has been taking measures to try to reduce negative impacts. Wineries are changing varieties to those better adapted to hotter days. Even Bordeaux, which you might call a bastion of winemaking tradition has approved new varieties for the region. Varieties like Carmenere and Malbec that were abandoned in France long ago for needing more warmth than was typical to ripen are being grown again. England is restarting its wine industry, and Champagne houses are starting to invest in vineyards there with the expectation that Champagne might become too warm for good quality wine in the future.
In Napa, some people are pruning earlier to promote an earlier start to the season and maybe get the harvest in before wildfire season kicks off. Everyone is investing in heat mitigation measures, whether that is shade cloth, canopy sprinklers, or different training methods. VSP (vertical shoot positioning) systems, where the clusters are exposed to the maximum amount of sunlight, used to be the go-to training system if you wanted to be considered a premium winery in Napa. Now you see many companies shifting to systems that offer more protection for the fruit, even going back to the much-maligned California sprawl. People have also been shifting away from rootstocks with poor resilience for water deficits to those with deeper roots that can handle more drought.
It sounds like the critics who are claiming the CA wines are getting better because of the higher brix created by warmer weather may be doing so at the behest of big producers of CA wine. I sometimes think that U.S. citizens have the dumbest palates on the planet.
As a fruit grower who struggles to get the highest brix I can on most of the fruit I grow, I’m often amazed at the crap that gets shipped here from CA where there is no excuse for anything less than exquisite fruit.
The first trees I planted here 17 yrs ago were paw paws. At that time, it was a pretty fringe choice, and people would occasionally scoff at the notion that such a fruit that after all “doesn’t grow here” would ever be capable of surviving let alone making fruit.
It’s an error to infer the adaptability of a plant from its ability to freely reproduce and compete in the native ecosystem and climate. The needs of a seedling are totally different than the needs of a full grown tree, and the dispersal mechanisms are also choke points limiting native range. When you remove these barriers and raise a plant to sexual maturity, it’s (potentially) far more able to thrive than common sense would suggest.
I remember reading about Kentucky coffee tree, which has a very small native range and is a facultative (maybe even obligate) wetland species. So from the looks of it, it would seem to be quite unadaptable and picky. Apparently that’s not the case at all, though. It’s easily grown in much of the US. It’s seed pods, which are full of sugary goo, were apparently preferred food of several megafauna, and while these megafauna were around, Kentucky coffee tree thrived, it’s native range stretching widely. Without these megafauna, the only thing that seems to simulate the effects of passing through the gut of a mastodon or giant sloth is landing in wet acidic swampy soil. Does it’s preferred habitat reflect its preferences as adult tree then? Not necessarily it would seem. And with such niche germination requirements and no animals to consume and disperse the seeds, it’s range has contracted dramatically.
And it’s totally a chicken or egg type scenario. You need seeds dispersed to beget trees, and you need trees to beget seeds. So the range and relative efficiency of the dispersal agent are crucial. Paw paw very clearly benefited by human dispersal. It wasn’t raccoons or possums that brought Asimina triloba completely up the Mississippi watershed.
Still, there’s the reality too that adaptability in terms of vegetative growth - I.e. ‘survival’ doesn’t guarantee that individual will be able to form viable seed or ripen fruit. We remove so many invisible barriers by cultivating something, and it’s a noble if potentially Quixotic pursuit to bring something from far away and coax it to adapt.
Also worth keeping in mind is that species are always moving and repopulation of species pushed south by the Pleistocene is not necessarily complete. I remember reading a synopsis of how this played out in terms of forest diversity in the Adirondacks. There were actually millennia in which the only endemic tree species were spruce (red, black) and white birch. Each time a new species arrived, it changed the whole dynamics (and tended to dominate). Viewed through this lens, it doesn’t really seem that outlandish to zone push, even ignoring changes in climate.
Paw Paw survived the last ice age so it must have some level of cold tolerance.
GrapeNut’s post is arguably the most interesting in this thread. He offers clear proof that grape growers are having problems associated with weather, and they are not problems that were present 50 or more years ago.
It is surprising how many of the currently known plant species were intricately linked with megafauna seed dispersal. While in Mexico, I saw the Mexican Breadfruit Tree which produces large edible fruit. It almost went extinct after megafauna disappeared. Another that has an unusual history is Osage Orange which today is an invasive in many areas. 500 years ago, it was limited to a range about 100 miles long by 50 miles wide across parts of Texas, Oklahoma and the southwest corner of Arkansas.
