Late Freeze and Christmas lights - in the ground fruit trees

Everyone thought I was nuts, but on the last 23 degree freeze night I set fires in the orchard. I dragged my big firepit down there and kept a nice big fire going all night. After covering them with sheets I put out metal pots and bins and such under the trees in full bloom and started charcoal fires underneath them. I topped the fires off with new charcoal a couple times and it stayed warm all night.

Another year I covered them with double layers of sheets and put a big activated handwarmer in the crotch of each around 29 degrees.

One year I drove around all night with a double propane burner on my atv, pausing at each tree in my circuit.

I am slowly grafting over to more cold hardy varieties but doing this gives me a sense of purpose and I see real results. Those uncovered have all black fruit and the ones I protect don’t. 2020 frustrated me so much after losing everything to freezes. It was sad to read about other harvests with nothing in my own.

My family says it’s my maternal instinct now that my kids are grown. I need something to mother and protect. I hate feeling helpless and this gives me some sense of control and purpose in a crazy world.

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I love this!! This is the mindset I have. While it isn’t absolutely crucial that I protect my fruit from the late frosts, I want to try. I’ve already carried the 3 potted dwarf apples inside the house this year. I was debating putting them in the ground, but they may stay in pots.

Its set to heat 3-4" of soil to 70f not adjustable.

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I’m guessing that means that the power is constant and that is as high as it usually makes the soil. 72 is fine for me, but I doubt that limit means very much if it doesn’t have an automatic shutoff thermostatically controlled. But I don’t know how it works.

Have you set up your system?

Bumping this thread now that I have my first ever fruit tree blossoms (asian pear) that I’m fussing over.

I tried to buy several “incandescent” lights off Amazon. All proved to be LED. I’m sure I can get some old-school ones on ebay. But not sure if they will actually do that much.

@mamuang — I think you’re around me (these trees are in an inner-ring Boston suburb). I’m just nervous and hand-wringing over my first baby buds, even though there is no flower yet. I know the May 17th frost damaged a lot of trees last year, not sure if trying to find old incandescents is helpful or not?

You asked the wrong person !!

I don’t protect my trees anymore. I did when I was newbies. Now that I am jaded :grin:, I just let them be. I have also stopped zone pushing. I figure Mother Nature wins more often than not. I don’t bother to fight her.

Have you seen the critical temperature for fruit development chart? It will give you some idea about what temp will damage fruit at what stage of development. It is not exact but it is a good enough for approximation.

haha — maybe I asked the right person, for that reason!

I’ve seen a critical temp fruit development chart I think from Michigan State. That one suggests that pears can generally handle a bit below freezing just fine, even into blossom and flower development. My Hosui pears should be good (they are zone 4 hardy in a sheltered zone 6 location), I’m just nervous as a newbie on my first outdoor buds.

If you are closer to Boston, you may be 6b.

Don’t worry, if the fruit abort, you will know. I have seen pears blooms covered in snow and survived. @clarkinks may have posted such pics.

After fruit development, we can still be hit by late frost. That’s when you may learn about frost rings.

I do not want to scare you but just want you to relax. Whatever happens, happens.

Next year you probably will complain about A pears setting too many fruit and thinning is a tedious chore.

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I so appreciate this thread, everyone! The forecast has winds up to 50 today and temps down to 30 tonight - with the wind still blowing hard. Since I live where springs temps are erratic, I only plant the most cold-hardy, late-blooming varieties of fruit trees. Right now, pears have just finished blooming; apples and an Evans cherry are in full bloom (not to mention lilacs!). I’m now convinced that any slight increase in temp around the trees would be dispersed by the wind; covering them would put them at greater risk of breakage. I considered setting up hot water sprinklers (I live at a hot spring) but read elsewhere that water + wind = evaporative cooling, making it even colder. I’ve decided to just stay cozy inside, have a second cup of coffee, listen to the wind, and go to sleep tonight with my fingers tied into a crossed position.

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I think my fingers are permanently crossed from frequent wishing. Best of luck to you!

:grinning: Mine too! Aha - That explains the arthritis!

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Where are you in zone 4? Please consider putting your location in your profile.

I totally agree about not covering trees in a windy condition. I did it one year. What a mess of entanglement!!! It caused more damage to my trees than had I left it alone.

Good idea! Done. Benton Hot Springs, CA at 5600’ elevation. It’s directly east of San Francisco, tucked among desert mountains in the rain shadow of the eastern Sierra, almost in Nevada. Spring is a matter of alternating warm spells and cold snaps, frequently accompanied by gale-force winds. I came here 50 years ago and quickly learned not to plant tomatoes until the second week of June. About 5 years ago I finally decided that fruit trees were worth the effort even if I only get fruit one year in ten. Two years ago a double-whammy hard frost not only destroyed all the fruit but killed an apple tree - by freezing off all the leaves, then just as they started to regrow, doing it again!

Reading this thread is what convinced me not to try covering the trees. The photo from growjimgrow caught my eye, and I saw your reply to it too. I also rejected the idea of Christmas lights - yes, I have a string of antique incandescent lights - because I realized this wind would just carry the heat away.


My tiny orchard. That’s the little Evans cherry blooming like mad at right - just behind the lilacs blowing in the wind. The snowcapped White Mountain range is in the background. The pointy one is Montgomery Peak and the bump on its left shoulder is Boundary Peak, highest point in Nevada, just across the state line.

So far the Evans cherry has been the only thing to produce a good crop. And this is the first year the Lilacs of Optimism got to bloom before they froze! I planted them mostly for my husband, who loves lilacs, and he’s away until tomorrow, so I really hope the flowers survive the night!

I’m not sure it’s quite as simple as the wind carrying away the heat. Some portion of that heat from the lights would be in the form of infrared radiation. Which is not affected by wind. That said I also take the position of just letting what will be be. My site is far too exposed to spring winds for covering to be feasible regardless, and the volume of lights I would need for radiative heat protection would probably be unreasonable.

Wouldn’t air that’s been warmed be dispersed by wind, regardless of the heat source? Anyway - good news - they seem to have made it through the night! One young tree is leaning. I though it was grown-up enough not to need a stake anymore, but in 50 mph gusts, apparently not!