We quit using pictures on temperature charts to predict fruit loss a few years ago.
Seems like the damage was often less than expected but sometimes worse.
Also quit cutting peach buds open after a freeze in order to predict damage…
Just a lot of anxiety over things beyond our control.
Looks like frost or freeze events kills most of the peaches about 1/5 years. Blueberries about 1/10.
Mother Nature is cruel to us fruit growers at times.
Loosing a crop is the worst part of this hobby. We may be heading into freezing temperatures so I’m a bit concerned. However, this article helps explain some of the caveats to freezing temperatures beyond just the temperature itself:
The one tip that stood out in the article was to irrigate ahead of time. The rational was that the extra moisture will help retain heat in the ground and release it over night when the temp drops.
We had two mid-20 degree nights after full bloom this year, and a very similar situation last year. Last year apples were completely wiped out but peaches needed thinned. This year peaches are just about 100% wiped out but apples appear loaded. Also this year–> labrusca grapes had some damage, but should have an OK crop, asian pears maybe 40% crop, american hybrid plums like Toka and Kahinta 50% crop, some euro plums 25%, some wiped out, only the mirabelles are loaded. Carmine Jewel cherries 40% crop, sweet cherries just about 100% wiped out second year in a row. Gooseberries OK. Paw paw flowers seem to have at least 50% survivaI, but I can’t tell if any set fruit yet. I actually don’t like reporting yet because so many things can still go wrong. PC is starting to show up (the battle begins). I got the first spray done, but have had 3 nights of rain since. Other than being bummed out about the peaches, I’m happy everything else shows as much promise as it does. It’s so hard to see the rhyme and reason dealing with frost issues. Most theories I have don’t seem consistent one year to the next. I think two exceptions are that Surefire Tart Cherry and Reine des Mirabelle seem to consistently be late bloomers.
Very good information. Things to consider.
Same conditions completely different results and when you look at the chart it makes it pretty clear that it is virtually worthless as a diagnostic tool- at least in and of itself. You are also, once again, confronted with the fact that when you are working with nature sometimes things happen that defy a known explanation.
None of the explanation of variations of susceptibility to freeze damage made by forum members here explains apples completely surviving a frost one year while peaches are completely wiped out and an absolute reversal the next. At least I cannot put an explanation together, maybe one of you can. Apples are always a bit later than peaches… always. They have similar frost resistance that declines as the flowers develop.
I don’t agree with that. A loot of this stuff has been studied quite extensively down to the specific variety.
One factor that murdetiizes trees here is not absolute temperatures but the temperature fluctuations; any trees that lose hardiness at the first false warm up is a dead tree once it gets cold again. Then there are many varieties where the effect of frost on flower and flower buds has been painstakingly tracked to determine how much they can take. Heck on my micro climate I get 40+ mph winds in sub zero temperatures for long stretches at a time, looking out of my window I can imagine the croupier yelling “all bets are off!”
Here in Alaska and in the Canada prairies when you get a hold of a hardiness study, where actual trees were put on the ground and tracked for years, you beeline for the only section that matters, how they did when a test year came. Usually it is the year that was too dry, temperatures hit record lows, and there was 0 snow coverage on the ground. You get entire swats of tree varieties with 80%+ winter kill and others that didn’t even noticed. Those on the last group are considered hardy.
Heck I have two Franklin trees on the ground. They are hardy enough and the flowers are reported to survive frosts where just about all other trees in upstate New York lost their crops to a late freeze. It would still be pointless to me if they can’t mature apples fast enough for our short growing season, so even if it is the hardest tree on the planet that alone would make it an ornamental tree :-/ even then I would try to cross it with another early variety apple, there are not many options for early cider apples.
Can you supply any of these studies?
This thread hasn’t been about tree survival up until now, but crop survival in relative cold at relative points of flower bud maturity. That might be a bit trickier to study that simply winter lows that trees can survive, although the latter is tricky enough.
It is not trickier to study but the information is on a variety-by-variety basis with very specific parameters so not as useful for broad generalizations. For instance on a very specific variety on a very specific rootstock at a very specific point on the flower bud stage, and an specific humidity range, it could be seen that it suffer 10% flower drop at 28f, and upwards of 90% flower drop at 24f. Basically repeat the data gathering for each permutation under each variety.
Heck here is one study testing just one parameter, the effect of rootstock on flower bud hardiness of peaches. It was found that one rootstock had a significant impact on enhancing Hardiness and yield of redHaven peaches but the same rootstock did not have the same effect on other tested peaches.
https://journals.ashs.org › arti…PDF
"Rootstock Influence on Flower Bud Hardiness and Yield of 'Redhaven …