This past winter was the worst winter we've experienced in decades with many days of continuous hours below freezing, three or four significant snow events and a record low of 5-6 degrees. I wanted to give others an idea what could likely make it long term grown in ground in zone 7b/8a. Here's a list of what died and what the tough survivors are:

Dead as a doornail:
Juanita
Calamondin
CiTemple Edible
Satsumas, all varieties
Nuclem
Lemonquat/marmaladequat
Changsha x Clementine
Sudachi
Tokyo pummelo
Yuzuquat
Bloomsweet
SanCitChang
10 Degree kumquat aka Nameiwa
Marumi kumquat
Meiwa kumquat
Dr Brown's seedless kumquat
Nordmanns seedless kumquat
OP Nagami
Croxton
88-2
6-15-150
Ujukitsu
Primosole
Orange Frost ChangSat
Changsha (It is noteworthy that I have one mature, fruiting potted changsha that I left out all winter that somehow survived. It is a seedling tree. This tree will be a good one to propagate)
Tiachang


The only surprising casualty from the above list is the 10 degree kumquat and OP Nagami kumquat. The have shown to be almost bulletproof down to around 8-10 degrees. I figured that they could handle 6 degrees

Alive:
*Ten Degree Tangerine, '2-2'
Dragon lime
*Yuzu (grafted and on own roots doing fine)
*TiaTri
*Ichang papeda
Ichang lemon
*(Trifoliate x Clementine) x Clementine
Ventura lemandarin (bark split on own rooted tree which is dead, but high grafted tree is bouncing back fine)
Tiawanica
*Swingle
Glen Citrangedin
Mt Olive Dunstan
Morton Citrange
*Dallas Dunstan
Keraji mandarin
Dimicelli
*Thomasville citrangequat (grafted and on own roots doing fine)
Sinton citrangequat
fast flowering/precocious trifoliate
varigated flying dragon

The surprise survivors here are Glen Citrangedin, Keraji mandarin and Dimcelli. Glen just didn't strike me as a very hardy tree but the trifoliate in its bloodline really helps it out. This tree is about 98 percent monofoliate. Dimicelli seemed equal to Glen to me but it sure can take some cold. Keraji is one of the best tasting fruits I have in general so I figured it would see the same fate as all the other good tasting or sweet citrus. It has proven to take 10 to 11 degrees in the past for me but now has proven itself to 6 degrees.

*doing great and getting ready to bloom or has already bloomed this spring

I forgot to mention that my US 119 looks dead but my friend in another part of Virginia Beach has a large tree and says his is still alive. Also my Tiawaniquat or Nippon Orangequat is coming back strong but I can't remember which of the two it is.

Thanks for the post. I'm sorry, the winter was terrible here too. What taste the best of the ones still alive ? Keraji mandarin maybe ?

The great experience, thanks a lot for the post.

Very interesting data. What is amazing is that Keraji being more hardy than satsuma and Chagsha. Also in the past I lost Glen at -12C (10F) and Thomasville either grafted on poncirus or on own roots is resistant here only to 8F.

Hi G.!

According to the archive of Weather Underground on Oceana Naval Air Station you had three cold waves with continuous frost and minimum:
http://english.wunderground.com/history/airport/KNTU/2014/1/30/DailyHistory.html?req_city=NA&req_state=NA&req_statename=NA

to -17.2 C, that is 2 degrees Fahrenheit. Perhaps it was a little warmer at your place due to the microclimate.

And in 1985 the temperature was -19.4 C in Virginia Beach:

http://english.wunderground.com/history/airport/KNTU/1985/1/21/DailyHistory.html

- that is even colder , but this year was a record for the last 28 years .

I'm glad that a significant part of your plants has survived; when a frost is so hard it really means a success of their frost-resistance and survivability.
It is unexpectedly that the Sudachi has not recovered yet because the seedling which I received from you shows much higher level of resistance than citrus Junos, and yet it also somewhat higher than, for example , citrus Taiwanica.
From my experience, the plants can germ and begin to recover from freezing even in July, if we are talking about seedlings .
Therefore , I hope that your Taichang will still recover if it is seedling. My Changsha is as resistant as citrus Junos. My Ventura has the same level of resistance and survivability as hybrids with Trifoliata and I think that your seedling will still sprout and recover .
Concerning Keraji it is a pleasant surprise, as from my experience it has showed a lower level of resistance than Kimbrough Satsuma (which is very hardy) and St Ann satsuma.
My Changsha x Clementine has showed a high ability to recover damaged tissues from the freezing.
To sum up, thank you! I hope the list of plants which have survived will still increase.

Citrus apocalypse in the Southeast, my owari is dead, a meyer that survived in ground for 2 years looks dead to the roots. I was stuck in my car for 2 days and so most of my tender pkants got iced over. Citrangequat is still green at the base, but I'm not sure if its grafted or own rooted. Pomegranate gone all the way to the ground, but resprouting from the trunk.

I didn't have anything die, but that ice storm did burn back quite a few branches...

Oh, I forgot... It's called "Global warming".

In fact we had an unusually warm winter. I could easily have left all my citrus outside without any damage!

In sharp contrast to USA, here in the UK (and I think in most of western Europe) we had the mildest winter for many years. Just a few nights down to -3C 27F. My greenhouse heating bill was way down on previous years.
I don't have many varieties planted outside because they generally hate the prolonged wet and cold. But citrumelo, ichang, ichangquat, and citranges all doing fine. And, of-course, no problem with poncirus or FD.
Only my small, newly planted out variegated FD was damaged. Not by cold, but by a snail that devoured each bud at every node. I think it will survive but will miss a year's growth.
Mike/Citrange

Our cold wasn't prolonged, just a few days. But, enough to do some damage.

G.

Thank you for your update. Very informative.

I have three Glen Citrangedins grown from your seed.
Two are stunted, the other is healthy. They all are heavily trifoliate.
However the largest one is showing a few monofoliate leaves
on the newest growth so hopefully it will start to look like the parent.

Alan

G, very sorry to hear about the hit to your amazing collection, but thank you so much for this update. Helps us all in the long run.

Tom The best tasting of the trees that are still alive is definitely the Keraji. Lemandarin has a milder tart lemon/mandarin flavor. My US 119 looks dead but I know of one that has survived here this past winter. When ripened properly it does get sweet but with a twang finish that doesn't bother me. Everything else that's left is basically sour fruits or sour fruits with off flavors.

The best of the sour fruits that made it is Yuzu, Thomasville, Ichang, Swingle (I don't find mine to have offensive off flavors), (Trifoliate x Clementine) x Clementine isn't terrible and has a really cool green flesh like a lime and Dragon lime is not bad.

Some say they don't mind the taste of Morton but somehow I can detect a skunky flavor when I sample it. My Ichang papeda is ok but doesn't have much flesh and is seedless. Dimicelli is about the size of and tastes like an unripe mandarin. Glen citrangedin is described as sour balls by a good citrus buddy of mine. They are about the size of calamondins but have a nice deep reddish orange color that stands out. I'd say the worst of what's left is the Mt Olive Dunstan. It has an exorbitant amount of resin in the peel that sprays everywhere if peeled and fouls the flesh if cut.

ilyaC I was pretty amazed too that my Keraji made it. Survivability can vary a lot. The large mother Keraji tree here in Virginia Beach where I got my initial start from appears dead but my two smaller trees are coming back. I figured the satsumas and changsha would probably die. I am very disappointed that my Yuzuquat died. It was getting to a mature size and I thought is might make it back but has not. I'll want to graft that one again because I really like that fruit. I've got to ask around and get a scion from whoever has one because dummy me didn't go out and cut back up scions of any of my trees before the extreme freezes came. I'd like to try Clementine x Changsha again also.

Did you bank the trees with dirt for cold protection?