Late freeze tonight...what to expect.

[journey11]

Well, a couple days of deceptive summer-like temperatures have prompted most of my fruit trees into blooming. It snowed this morning and it is supposed to get down to 24 degrees here tonight.

I found this very handy pictorial chart of fruit tree bud stages (PDF file) and at what temperatures to expect enough damage to lose your crop. Sounds like most of us here in the Midwest to Southeast will be biting our nails tonight.

According to the chart, I can expect to lose my apple crop this year on my two large trees that are already well in bloom. I have one smaller tree not quite up to bearing age. It hasn't bloomed yet. The big tree on the farm probably hasn't bloomed yet either. My peaches should be safe though. And my two young pear trees aren't blooming yet either, but I didn't expect much out of them this year anyway.

Not sure about my blueberries, since they aren't on the chart. They are in full bloom, so I'm going to cover them with plastic row covers and plug up a heat lamp.

 

[Smart Red]

Thank you for that handy pictorial chart of fruit tree bud stages, journey11. I'll be using that in the future to help me decide what to do when.

 

[journey11]

Here's what I found on blueberries, from this site from NC State University:

Cold SusceptibilityBlueberry blossoms and small berries are considered hardier than the blossoms of most fruits. Temperatures must drop below 28 oF for economic losses to occur on highbush blueberry (Vaccinium corymbosum L.). The temperature at which freeze injury begins to occur depends on the stage of development from dormant flower buds through young fruit. During the winter, dormant flower buds of highbush blueberries will survive temperatures as low as -20 to -30 oF while the less hardy rabbiteye (V. ashei Reade) have survived -10 oF but are often damaged below 0 oF. As flowerbud swell progresses, cold tolerance decreases. By the time individual flowers begin to protrude from the bud, temperatures below 20 oF will begin damaging the most exposed flowers. When corollas have reached half of their full length, temperatures below 25 to 26 oF will kill the complete flowers. However, at this stage, blossoms on rabbiteye blueberries may receive corolla damage at temperatures as high as 30 oF. The corolla withers, but usually remains attached. The withered, unopened corolla prevents bee pollination and otherwise undamaged flowers drop rather than developing into fruit. Corolla damage to unopened highbush flowers that prevents pollination is seldom a problem with highbush blueberries. When the blossoms are open, a temperature of 27 oF for more than a few minutes causes damage. Immediately after corolla drop and before the berry begins to swell is the most sensitive stage. A few minutes below 28 oF will result in damage. As the berry begins to enlarge, susceptibility is similar to the critical temperature of 28 oF for open blossoms.

Definitely need to cover those blueberries. Sprinklers aren't an option available to me.

 

[Smart Red]

Thank you again, journey. It got down to 21º last night, but none of my buds have started expanding enough to be problematic -- I hope!

 

[journey11]

Good luck, Red! Hopefully yours haven't gotten ahead of themselves like mine have!

 

[Nyboy]

Good luck same happened last year.

 

[Carol Dee]

Great chart. Your weather sounds much like ours, It was Sunny and 80 on Saturday. Cool and Rainy Sunday. COLD and SNOWING Monday. We woke to 24 degrees this morning. So we start the slow warm up again.

 

[canesisters]

I have no idea what I'm talking about.... but gonna toss this out anyway...

What about trying what the fruit orchards do and spray a fine mist of water over them as it starts to drop into the danger zone???? Something about the ice protecting them from the colder air????????

 

[baymule]

This stinks. I am ok, frost wise, but I am sorry for ya'll that are getting a whammy all over again.

 

[journey11]

I have no idea what I'm talking about.... but gonna toss this out anyway...

What about trying what the fruit orchards do and spray a fine mist of water over them as it starts to drop into the danger zone???? Something about the ice protecting them from the colder air????????

I'd heard of that and I might have otherwise tried it, except I don't wanna go out in my jammies tonight. LOL