Author Topic: Hybrids in zone 7a after a low of 12f (-11c)  (Read 501 times)

vnomonee

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Hybrids in zone 7a after a low of 12f (-11c)
« on: January 14, 2021, 05:01:41 PM »
These are all 2 year old seedlings with the exception of the Poncirus+ which is grafted onto regular Poncirus. All without any protection, they are all up against a brick wall. So far the lowest temp has been 12f which happened last month, I covered them in fresh snow before that happened. Daily temps have been above freezing all winter which has been mild overall. I don't have any long term goals for the plants. I took cuttings and rooted them before the winter so if they perish which they might I do have backups. 

Poncirus+




Citrumelo (noticed these less narrow and more round trifoliate lookin leaves with yellow coloring) no damage aside from some leaf curling



Tai-tri no damage aside from some leaf curling



Yuzu has the most damage but it's still alive. Some leaves have no damage, others are dried up or curled up. Young branch tips turned white (desiccation?)





kumin

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Re: Hybrids in zone 7a after a low of 12f (-11c)
« Reply #1 on: January 14, 2021, 06:54:34 PM »
vnomonee, it's interesting to see the comparisons between these selections. Being located 100 miles to your west in zone 6b it's obvious your climate is a bit friendlier than mine. Having considered Yuzu to be questionable at my location, your photo confirms it. With the exception of Yuzu, I have all the selections you've shown.

My Poncirus+ is also unaffected to this point. Your 5* Citrumelo looks noticeably better than mine, likewise with the TaiTri.

The lowest temperature to date has been 10 degrees, yet these trees look to be in poorer condition than yours.


 5* Citrumelo top grafted on Poncirus (Jan 13 2021)



Poncirus+ top grafted on Poncirus (Jan 13 2021)


TaiTri top grafted on Poncirus (Jan 13 2021)

« Last Edit: January 14, 2021, 07:24:39 PM by kumin »

vnomonee

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Re: Hybrids in zone 7a after a low of 12f (-11c)
« Reply #2 on: January 14, 2021, 07:47:31 PM »
Hello Kumin

The pictured Poncirus+ is the one you sent me. Looks like it will come through the winter just fine

Your 5* Citrumelo leaves look very much like my freeze damaged Yuzu leaves. While I didn't quite hit your low by 2 degrees F I think the brick wall surrounding the trees (the wall wraps around like a sideways L) adds a few more degrees over the lowest temp. There is also an aluminum shed to right of the trees as well as an above ground pool which if not providing additional heat probably helps to block the cold wind


Millet

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Re: Hybrids in zone 7a after a low of 12f (-11c)
« Reply #3 on: January 14, 2021, 11:04:12 PM »
Poncirus is deciduous by nature.  My FD loses its leaves during the winter even growing in a warm greenhouse.  Therefore, deciduousness can be effected just by shorter day length.

Citradia

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Re: Hybrids in zone 7a after a low of 12f (-11c)
« Reply #4 on: January 15, 2021, 08:50:01 PM »
I would be ready to cover and possibly heat your zone 6/7 hybrids when you go single digits. If noticed a lot of loss of previous year growth/wood and if freezes for days at a time, trunks will split near the ground and tree will die in early spring even if there is a temporary flush of growth.

vnomonee

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Re: Hybrids in zone 7a after a low of 12f (-11c)
« Reply #5 on: January 15, 2021, 10:21:45 PM »
Thanks Citradia, I have some frost cloth and some jugs which I can fill with water. Unfortunately I would only have passive protection unless I run a cord somewhere to get string lights up for heat. Hopefully won't see single digits this winter polar vortex be damned lol

Citradia

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Re: Hybrids in zone 7a after a low of 12f (-11c)
« Reply #6 on: January 16, 2021, 06:56:36 AM »
Yep. Iíve lost a lot of hybrids using only passive protection with frost cloth, plastic sheeting, hoop house, water barrels, jugs of water, etc. when itís polar vortex and below zero all night for several days or even below freezing for a few days with a low of 7 degrees. I do have drop cords going to each tree with small space heaters controlled by thermo cubes, and I am ready to cover even hybrids if we go into low teens or single digits. Iím just tired of loosing trees and waiting for them to come back from roots. You may not loose them this year, but you will eventually without protection unless with global warming our days of single-digit winters are over.