Citrus damage after freeze

[tedburn]

Hardyvermont, thank you. Good information. Also interesting that Sugarbelle ( tangelo minneola?) can take so deep cold, thought that she get killed earlier.
Mine are 2 and 3 winters now in ground and the biggest are Sanford Curafora and Keraji with about 1,5 m hight.

[manfromyard]

I was in Tennessee when the cold hit.All my citrus had extreme leaf damage. A huge issue is that it stayed so warm before and after. Icang, Thomasville, Meyer, all with what looks like >90% leaf loss. Even my two rosemary bushes got burnt badly.

[edweather]

Wow, that was a cold snap. We had a 5 day cold snap, and the temps were in the low 20s for 4 straight nights. We picked the fruit ahead of time, and used propane patio heaters and box fans to try and keep our 5 trees warm. Noticing leaf drop, but not much damage. Thankfully no blossoms or tender growth.
 

[Perplexed]

Can't say for sure now until spring or summer, but here is an minor update so far. 9F.

Citrus taiwanica has some stem damage and leaves still attached, looks sad. It's a 1 year old seedling so it might get hardier over time.

TaiTri looks good, just some minor defoliating no stem damage.

5* Citrumelo is the same boat, leaves dropped but no stem damage.

N1Tri x Citrus,  Ichangstar60 x Citrus, Citrus hongheensis x Citrus lost label for them so its F2 of one of these three. Some appear dead visually and all of them are defoliated but some have green stems.

More updates in May for more accuracy regarding if any will resprout.

Some ornamentals like Persea liebmannii are unphased.

[Perplexed]

Over 36 hours below freezing also

[orangedays]

I can finally estimate the damage to my citrus hybrids after this  December's freeze. The temperature dropped to 11 F and stayed below freezing for around 48 hours after a warm mild Fall. I had a variety of crosses to a Dustan citrumelo seedling. I planted these in a row in a very exposed area, with  a changsha seedling every fourth tree to act as a control. These were all 3 years old and stem diamerter any were from 1/3rd to 1 inch thick and mainly bushy around 3-5 feet tall. The chansha were around 6-7 ft.  The idea is the seedling should do at least better than changsha to be worth keeping, that is they stems stayed a healthy green and  now showing signs of regrowth.

3 of 9 Changsha X Dustan are keepers
4 of 15 Juanita (f2) X Dustan are keepers
1 of 3 Owarie X Dustan are keepers

These all lost all or most of their leaves. The changsha seedlings were interesting. They all died back to some extent. The stems did not crack but developed a grayish cast. They were all around 6-7 ft tall.  Overall they look worse than they were. Some are dead to almost to the ground while other are sprouting from the grayish stems over 5 ft and growing well. Spring has come on so early this year, I think they are all at risk and I may lose them still. But as controls they had more variability than I expected.

Of the poncirus hybrids, most appear to have very little damage. The PT X Hamlin suffer the most. I think the mulch formed a frozen crust around the trunks as the damage is on the primary stems where the stalk leaves the mulch. 3 of the 17  changsha X PT died, the rest look unharmed. All 3 fukushu X PT hybrids look well. I also planted out 5 Hirado Butan X PT f3? seedlings (from hardyvermont). These were small and under heavy mulch. They all survived and look pretty good. I lost several tangelos, red grapefruit, Hamlin, and Amber sweet that were under cover with a 60 gallon water barrel. The Okitsu tangerine under cover with water barrel, came through all green and leafy.  I hope to cross it with Dustan this spring if we don’t have a late freeze...

[johngonole]

We had four or five days in a row of subfreezing temperature going down into the low 20s three nights in a row.   Even during the day it didn't break 32.    Lost our Meyer Lemon.   Had two Owari Satsumas that were young trees.   Lost about a years worth of growth.   Smaller branches on the perimeter of the trees died.    I only covered them with light covers.  I have no doubt these trees would go undamaged with typical North Florida freeze where it only drops below 32 for a few hours or only had low 20s maybe one night out of the season.    But we had a long sustained freeze.    Overall pleased since all other citrus I have tried growing in N. Florida haven't lasted a single winter. 

[Millet]

In Florida try covering them with a heaver covering, and put an light bulb under the covering. Not LED type.

[tedburn]

thank you .
Thats also a point that freeze abd sun is extreme challenging and shade helps a lot to get minor damage.

[Citradia]

I’m so discouraged after the hard December freeze, I am close to quitting citrus altogether. I lost or suffered severe damage to everything except poncirus. My power was out for two hours during a 2 degree freeze with a high of 8 degrees and below freezing for about five days. That means my heaters were off in cold frames and we couldn’t get generator to start to get heaters back on. Then, I figured out I had used too long of an extension cord to supply power to my heaters in the valley orchard, so basically those citrus got no power or heat all winter until after the week of hard freeze, so they’re all dead except the side of the yuzu that was literally touching the side of the big water barrel.

Total losses:
Rio Red grapefruit ( heaters too small)
Seville
Bergamot ( too damaged to keep but alive)
Shiranui ( valley- no power)
Sugar Belle ( valley-no power)
Ichang lemon ( valley-no power)
Citradia air layer ( covered only, no barrel)
Citradia on poncirus air layer unprotected
Citrumelo 80-5 unprotected
Thomasville unprotected
Dunstan unprotected
Benton unprotected

Alive but severely damaged by house and got power back after two hours without it:
Owari
Kimbrough

Minimal leaf loss or tips of leaves damaged with power off two hours:
Seedless Changsha on flying dragon
Meiwa kumquat ( gets heat from French drain on south side of house)
Croxton grapefruit ( French drain south side of the house)
Saint Anne ( has two large barrels up against west side of tree)

My best survivors that didn’t have ground heat from French drain and only water barrels in a cold frame when heaters went out are Saint Anne and Changsha. My potted grafted-on-poncirus citrumelos and citradia trees were also undamaged.

[vnomonee]

We got down to 5f for a few hours one day and then again 1f for a few hours later on. My tai-tri and citrumelo unprotected look alive, just some tip damage on younger growth. Prague grafts on taitri and poncirus look ok, some brown spots (maybe mandarin cells damaged?). Ninkat x poncirus lost youngest growth but otherwise alive. all poncirus+ and precocious poncirus is alive. yuzu is dead to the base again. morton graft on citrumelo dead, morton on tai-tri looks alive.

[tedburn]

I’m so discouraged after the hard December freeze, I am close to quitting citrus altogether. I lost or suffered severe damage to everything except poncirus. My power was out for two hours during a 2 degree freeze with a high of 8 degrees and below freezing for about five days. That means my heaters were off in cold frames and we couldn’t get generator to start to get heaters back on. Then, I figured out I had used too long of an extension cord to supply power to my heaters in the valley orchard, so basically those citrus got no power or heat all winter until after the week of hard freeze, so they’re all dead except the side of the yuzu that was literally touching the side of the big water barrel.

Total losses:
Rio Red grapefruit ( heaters too small)
Seville
Bergamot ( too damaged to keep but alive)
Shiranui ( valley- no power)
Sugar Belle ( valley-no power)
Ichang lemon ( valley-no power)
Citradia air layer ( covered only, no barrel)
Citradia on poncirus air layer unprotected
Citrumelo 80-5 unprotected
Thomasville unprotected
Dunstan unprotected
Benton unprotected

Alive but severely damaged by house and got power back after two hours without it:
Owari
Kimbrough

Minimal leaf loss or tips of leaves damaged with power off two hours:
Seedless Changsha on flying dragon
Meiwa kumquat ( gets heat from French drain on south side of house)
Croxton grapefruit ( French drain south side of the house)
Saint Anne ( has two large barrels up against west side of tree)

My best survivors that didn’t have ground heat from French drain and only water barrels in a cold frame when heaters went out are Saint Anne and Changsha. My potted grafted-on-poncirus citrumelos and citradia trees were also undamaged.

Oh Ctradia,that s really hard, I' m sorry for you. But don ' t skip your citrus,  enjoy your survivors and perhaps invest in more hardier citrus as Prague and keep them on Poncirus.
And perhaps optimize still your passive protection with water barrels and fleece and perhaps places with not to early winter sun.
Enjoy the new sprouts of your survivors.
Regards Frank

[Citradia]

Thanks, tedburn. I’m planning on putting my Prague on poncirus and citrumelo on poncirus that are currently in pots in ground in cold frames to test them out for next winter. I’m scaling back though. I’ve had too much to protect. Too much work for no reward. It also looks bad having tent city in the yard seven months out of the year.

[Perplexed]

So far only 5* citrumelo, taitri, and dragon lime are showing signs of life and are flushing now. Everything else is either dead or major stem dieback, but the wood for the some species is still green. Will be more specific probably in May or Summer so I can see the full extent of damage.

[manfromyard]

Thanks, tedburn. I’m planning on putting my Prague on poncirus and citrumelo on poncirus that are currently in pots in ground in cold frames to test them out for next winter. I’m scaling back though. I’ve had too much to protect. Too much work for no reward. It also looks bad having tent city in the yard seven months out of the year.

I have also started scaling back. I have bought  a few replacements, but now will be maintaining less trees. The hardiest ones stay, but I've reduced my plants by a lot.

[hardyvermont]

8 F, 13 C was not cold enough to differentiate a lot between most hardy citrus.  Both types of 10 Degree Tangerine appear to be more sensitive to the cold than expected, leaves curled more than most.  Brown Select, Changsha, Keraji appear to have done well.  Sugar Belle will probably lose its leaves, but seems to have survived.

As Millet said, more time was needed to find the true amount of damage, which was much worse than initially appeared.  Posted elsewhere on this forum are the evaluations.