Frost damage and the "lies" experts tell

At the end of March we had a frost that got down to not below 19 degrees but I was only mildly worried, peach buds were starting to swell as were early apples a bit. Against the wall of my house, there were some open apricot blooms but cot trees out in the open weren’t showing color yet. J. plums were just starting to show some green.

According to the above chart there shouldn’t have been much to worry about, but almost my entire plum crop, both Euro and J. appears to be wiped out as are my early flowering apples and nectarines.

I have a pretty good crop of apricots against my walls- hard to believe they were so well protected on a breezy night. Alfred, as usual, faired especially well, but it is still a light crop.

All the flowers opened and were beautifully tended by native pollinators- then most just shriveled- apparently the result of destroyed ovaries but there was never any tell-tale brown in interior of the green below the blossoms.

Chart be damned! In this field, research is far too limited to ever be definitive, IMO.

The last few years my orchard has been leaning on nectarines, but I’ve kept enough peaches to keep me in fruit throughout the season and hopefully enough for the freezer to take me through winter. But it’s only mid-spring.


I know you are just kidding but why beat up science over this? It is applied science. Conditions vary, ie radiation freeze vs windy freeze. Cold a couple of days prior to the freeze vs warm just prior. Lots of things factor in.

Those charts have been pretty accurate for me.

That said I’m not sure how the charts were developed: natural in field freezes which could take 50 years to flesh out or lab tests in a freezer measuring the heat pulse as the buds freeze.

I would think it would have to be lab work. Field freezes in any commercially viable area are too rare to ever hit all the stages for all the crops. No one in a highly freeze prone area would attempt the tests outdoors. Michigan doesn’t have many natural freezes.


@alan @fruitnut

It often comes down to a degree or two. Wind is sometimes my friend or foe depending on the situation. The next generation of weather charts may be a meter that factors in variables but we are a long way from that.

I was kidding, but with a point. Take your anecdotal observations and the leaps of scientists when evaluating the significance of their own research all with a grain of salt. Fatal freeze temps for fruit tree flowers research doesn’t receive quite the kind of funding that cancer research does but even in highly invested fields of research, assumptions change as research continues. It is a human tendency to over-estimate the significance of ones own observations and even research (if one is to believe the suggestions of evolutionary psychologists drawn out of their tricky research).


You seem to be missing the point of the charts. Life is not a game where when something hits an exact parameter, say 23.47f, something automatically happens. Just like no family has 1.93 children no tree exist in the exact parameter the chart points to, no tree is the exact tree as the typical alluded tree, no tree has experienced the same epigenetic adaptation, no tree is at the same degree of hardiness based on the exact temperature fluctuations, experiencing the same stressors, have gone through the same prior year cropping, received the same pruning, at the same time of the season and growth point, yada-yada-yada ad nausea.


There are more factors in freeze damage than just temperature. 2 years ago we had a really heavy frost (ice crystals) one morning. Even though the temperatures were not very cold, 32 to 33 degrees, I had more freeze damage than I normally would with temperatures in the mid twenties. I also think damage has a lot to do with the status of the plants, if they have started to break dormancy you will get much more damage.

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@don1357 I particularly think of 25F as may be a problem and may not. I worry pretty bad at 23-22,20.

You nailed it in my opinion.


I think of it like this: “Science is objective, scientists are sometimes not”


Often, the temperature is not the determining factor. Humidity and wind may be the culprits. I’ve seen hard frost at 35 degrees that killed tomatoes. I’ve seen temperatures down to 22F with a stiff breeze that prevented frost where some tomato plants were killed outright but others were unharmed. I don’t rely on forecasts. They are wrong about half the time.


Wow, I can’t believe some of this response to my comments about the chart. I just found out that half of my crop is destroyed and you are defending a chart- one I wasn’t seriously railing against- I don’t even really care about the chart, but reading it, anyone would be surprised by the level of damage I ended up getting- it was certainly off the charts- it came with no caveats. .

I was hoping for a bit of sympathy and also to point out that the chart was not very reliable for me this year. Man, if I can’t get any sympathy for losing half my crop on this forum, I don’t know where I’m going to go. I guess it’s my fault because the title sounds like I’m attacking the experts, but I’m supposed to be an expert in growing fruit.


I must say I love my haskaps. Last year I was given a full grown bush to add to the herd; it was already greening up and pushing flower buds. Digging it was a pain because over half of the sprawling roots were encased in a sheet of ice. I had to break through the 5-inch slab of ice, get under, and pry the whole thing up. These are the conditions haskaps feel confident to green up and flower. Heck right now they are in full bloom and judging by the frozen hoses I find every morning I would say things are still getting bit chilly at night. It doesn’t bother the blooms at all.

To that point, about 3 weeks ago the forecast here called for 38 degrees with a chance for some frost. I discarded the news since it was above freezing and, as a result, all of my figs lost all of their leaves and about 1/3 of my strawberry blooms were toast.

I strongly agree with this, based on my own experience. I’ve lost half a dozen young apple trees on MM111 to frozen cambium within the past decade due to late cold snaps following a warm spell in January. This is in coastal California, where we’re not subject to extreme winter (or summer) weather, but we’re certainly experiencing unusual variations in weather patterns of late.

Not challenging you Alan. You can’t rely on the “charts” because they rarely cover all the factors involved. I have been there and done that with losing a crop because of a heavy freeze.


You have it, for what it’s worth. These losses are frustrating and obviously difficult to predict and guard against.


Same with my arctic raspberries. Arctic raspberries are hardy to something like zone 2 and spread like crazy compared to regular raspberries. I do find some plants are much more hardy to cold temperatures than others. I remember when I started growing again as a adult and grew peppers. I remember I had temperatures in the 30s or 30s that were below freezing and they hung on for a frost or two. Meanwhile I had a hydrangea that did not survive winter when it was supposed to be hardy yo zone 3 and I am zone 5.

I wonder about the accuracy of the temperature readings. I’ve gotten several thermometers (one mechanical, one liquid, and one digital) and they rarely agree. And the digital gun one gives widely different readings (10F+ swings), when panned over the landscape.

Does that mean that the later ones seem to have set, or the jury is still out? I’m referring to the necs, as I know some apples may still be in bloom. Hopefully you’ll get at least a partial crop. Which could just mean less fruit to give away and maybe a bit less thinning.

I don’t think I was badly affected. Maybe some peach/plum/apricots got thinned a bit, but I still see fruit on all 3 types. I haven’t checked each tree though.

At other sites a town or two over, some of the apricots flowered but didn’t set, though that could just be because they are only on their 2nd year in ground. At least a couple seem to be holding onto their fruit as are two 2nd year peaches. The older peach at another site also seems fine.

I got bad peach leaf curl at one site (2 of 3 trees- maybe the 3rd, a seedling of Heath Cling is resistant), so I’ll need to do a dormant spray there next winter. I think I sprayed fungicide at bloom (I’ve started spraying apricots and sour cherries hoping to get rid of blossom blight and figured peaches could have it too), but I guess I need to do it earlier to avoid PLC.

In a worst case, even if your orchard comes up mostly empty, you may be able to sample a bit of fruit when you take care of the various orchards. I bet that many of them, at least any which are out my way, will have at least some fruit.


I have Heritage raspberries. I’m on zone 4 but get 40+ mile an hour winds throughout the winter. When the temperature is well below 0 and those hit for a few days in a row all bets are off. I’m glad to report that the heritage raspberries come through with flying colors, wake up early, and keep cropping until the first or second frost.

You do have my sympathy Alan and also my appreciation. I get a lot out of your posts and appreciate the experience you share. Some years are brutal no matter what you do and I’m sorry to hear that it is one of those years for you. I like looking at that chart to help manage my expectations, but then I agree sometimes they are totally off the mark. The longer I grow stuff the more I believe everything is about the microclimate and nature will always surprise us.


I have had many years gaging my relative temps to what is posted for Carmel on wunderground and am confident I didn’t get lower than 19, especially considering it was a breezy night which reduces variations at nearby sites. All my peaches have at least some fruit except maybe Flavor May and Goldust and I can’t find any fruit still ripening on my nectarine trees. My early flowering apples got blasted but Goldrush, Pink Lady, King David, Zestar and to a lesser degree, Newtown are setting fruit. Empress and Castleton plums still have some too.

By having some fruit, I mean its come a lot farther on these trees than the ones whose blossoms quickly dried out after bloom. I’ve been worrying about this for about a week.

Even early flowering apples come out later than peach blooms and this is the first year in almost 30 that I’ve had peaches and lost part of my apple crop due to frost.

Old time apple growers around here sometimes say you lose the apple crop once a generation, but peaches about once a decade. I’m beginning to see why most never planted many nectarines.

For my diet, nectarines are my most important fruit I grow when I have them. Hopefully I get enough peaches to take their place- I will get used to their lower brix.