Penn State just sent out the critical temps for damage to various crops in their newsletter below.
Last year it was 23 degrees when my peaches were in full bloom and I still had a a pretty good crop. My results are somewhat like the one Olpea described. It looks like the blooms may be more tolerant than what the charts indicate. I hope so!
During a radational frost on a still night, the micro-climate of the orchard makes a big difference in the outcome. A 10 foot elevation change with good airflow can help break the temperature inversion and pull the warmer air into the orchard. I believe that may be what helped me last year.
Drew, those charts are guidelines, not absolutes. Olpea has lost crops from winter lows less than that. It all depends on how hardened the buds are at time of frost. Apparently, all the mild weather that comprised most of winter left the buds in a less than sturdy state (too much water in them).
I expect the temps were actually not as cold in some of the trees because my sensor is located in a low point.
After 2.5 hrs of driving around looking for a propane heater this weekend, I found one less than 2 miles form home…go figure.
Covered all the fig trees with 3 layers of Agribon AG-19 and ran the heater on low all night. Nothing froze, but tomorrow night we are looking at temps in the teens so fingers crossed. Nature sure is a mother!
I would think if it becomes that cold, microclimate, hardiness aside, you should examine for possible damage. I would not assume no damage. That is what i was commenting on, like you were surprised damage occurred. And well you should expect it. You described temps as a mere -12. When I see -12 I’m in awe of the power of Mother Nature to mess me up. At -10 I expect damage.
Strange how you got that cold and I didn’t? Well lady luck may leave soon with these nightly lows.
My daffodils are saying "what cold?’ Time for a peach-daffodil GMO.
Forecast is 23 tonight and tomorrow. Last night was supposed to be 31 but was 39. Maybe I’ll luck out and get 6 degrees.
Peach tree is past full bloom, pears are almost opening, apples have another week or so, and blueberries are just starting to bloom. Hope nothing gets too damaged.
The “Thinning g-d” will not get his tithe (nithe?) this year.
But good to hear the good news. relaxed relieved and triumphant YEA !!!
I am going up to my pace tmr’w to check. I think I am far enough north of Alan that my trees haven’t woken to the extent that his did and should be OK.
Maybe this year I will be able to help @alan in stocking his nectarine freezer.
I know your commercial nursery is your livelihood. All this cold spell (after unusually warms temps before) I’m seeing my pear grafts go, but apple grafts aren’t. Little impact to me compared to my peach crop, but I thought it worth mentioning.
That’s true Speed. Some trees look very thin, but a lot are looking good. Of course mother nature doesn’t thin very accurately, so I can already tell a lot of shoots w/ no fruit will need to be pruned out, but that goes much quicker, than thinning.
Just made a short trip out. The stinging ice balls coming from the sky are fairly nasty. We currently have freezing rain that should taper off in about an hour. Then freeze overnight and continue to rain tomorrow.
Mrs. G.
Like I said, I thought my peach buds were dormant. Upon further review, they were dead as door nails after the deep freeze in mid Feb.
Now that we have had two days of we snow and tempat about 21 last night and tonight and more to come, I am hummimg Que’ sera’ sera’.
All I can say is I’ll go easy on peaches and nect are they are the most tender of fruit trees in my experience here. Cherries, A. Plum and E. Plum follow suit.
I’ll grow more apples, E. pears and E. Plum as the ones I have bloom the latest.
Wanna sing chorus?
I have Harrow Sweet and Blake’s Pride as E pears and KG, 20th Century and Hosui as A. pears
Harrow Sweet and KG are about to bloom, yikes. Followed by 20th C., Hosui and BP which is always a late bloomer. I hope BP is as good as advertised. It’s my kind of fruit tree, late bloom, disease resistant and good tasting (per literature).
Yes, I can hear you sing through all the snow and wind (and sometimes hails). Whatever will be, will be.
Michigan State has published a wonderful chart on frost damage.
I used KDL 3oz / gal plus vinegar 3 oz per gal per Bob Purvis (NAFEX) for the last two years on my apricots and had zillions of fruit.
Peaches have been fine here probably about 7 out of 8 years and when they don’t burn they crop reliably. I think they are about like J. plums in this regard because the J’s may be hardier in winter temps but are somewhat more susceptible to spring freezes and all plums can be lost to continuous rain in wet years.
E. plums can sometimes be unreliable croppers as can pears (besides my beloved Harrow Sweet- so far). Apples are, of course, the most reliable of all if you do what’s needed to avoid biennial bearing.
The trick is to grow a range of fruit but the problem is how quickly the wonderful becomes the required. I can’t imagine a winter without frozen, tree-ripe nectarines after getting used to them the last couple years.
My peach story:
2014 bad, bad subzero temp wiped out most flower buds (not all because the trees were healthy)
2015 stinkbugs wiped out 95% fruit
2016 another subzero wiped out probably most if not all peaches and nect.(my first hope of nect/Easternglo).
I think the buds are even more vulnerable as the weather has been freezing cold in 2013/2014, 2014/2015 winters. This past winter was overall mild but the 2-3 of subzero nights had done quite damage as the trees have withstood a few tough winters in a row.
I am glad I’ve planted all kinds of fruit trees. Something just gotta stick.
I just remembered that I have one of those small portable electric heaters that people stick under their desks. Maybe 6x6x9". That thing would probably work well for protecting a single tree. It gets much hotter than a light bulb. Anyone ever used one?
I’d actually be worried about toasting the tree- whipping it back and forth between hot and icy cold, as the wind blows. I am tempted to drop a 8 hour heat pack into a bucket and leave it near the trunk of the tree. Maybe the bucket can form a column of warm air rising? Of course, it may just melt off the ice when it is needed…
Hopefully the layer of ice on everything will help. I gave up on getting the large tarp onto my trees. Not the kind of thing you want to do in dark icy conditions. I think I gave up in time to not damage my trees (or myself) too badly.
It is currently 27.6F in my yard, while the WC reports 27, so maybe I can stay a degree above the forecast low, which has gone back and forth between 21 and 22F.
A couple days ago, the low came at about 4AM and it stayed cold till 7AM. Rather brutal, but the lights seem to have worked, the buds look good, but I have 4 more cold nights coming, not good.
A bad night right now at 12:30 AM it’s 22F. So the cold will be here all night.
relaxed 
relieved 
and triumphant YEA !!!