It was a rough winter for my citrus in zone 8b of central Tx this year, both in ground and potted. Two of my in-ground citrus died from the top and the bottom first with the top probably being frost bite. Apparently the bottom was dead too, as the middle remained green, while the bottom turned grey and died as well. One of them, supposedly an Ichandarin, even sprouted new growth from the middle before it realized the bottom was dead as well. Is this all frost damage, or does it sound like maybe more is involved? See pic at http://cid-b426ff21b024d8d6.skydrive.live.com/self.aspx/Citrus/100%5E_1633.jpg

Heath74 does the tree have damaged bark? If the trunk of the tree froze and the tree was growing the sap freezes and the tree dies after it starts growing in the spring. Look for loose bark on the trunk , if the tree was grafted it might sprout below the graft or above it.

I'm certain frost was part of the problem, definately what caused die-back from the branch tips. But there was nothing even close to a frost after the tree started showing really good signs of perking up. It just started shriveling, as seen in the pic. So I guess what I was wondering, especially since I had two trees die in this manner(the top first, being obvious, the bottom next, harder to discern(no loose bark), then the middle dying last) is does it sound like I have some sort of root problem also? I decided the best way to anwer that is to leave it long enough to see if anything does resprout from the roots. Any other thoughts?

It wood be good to have pics of the entire tree.

I read that it is possible to have no damage to the leaves and upper branches, but severe damage to the trunk after a freeze. Anyone ever see this? I thought that citrus freezed from the top down and from the outer branch tips progressively to the center.

You can protect the main branches and trunk from freeze damage with white paint or white wash. Do not use oil paints though!



The bark can die in patches without splitting from sunburn the summer following the freeze. It will usually heal though if the second growth flush in the spring/summer following the freeze does not die back. High temperatures in the mid 90s or higher during the summer is the real test for freeze damage though.

Here are 2 updated pics:
http://cid-b426ff21b024d8d6.skydrive.live.com/self.aspx/Citrus/100%5E_1680.jpg
http://cid-b426ff21b024d8d6.skydrive.live.com/self.aspx/Citrus/100%5E_1681.jpg
As mentioned, I realize frost was part of the problem. I just want to rule out any type of root problem, like footrot. It just seems strange to me that the plant was well enough to sprout new growth, as if only the tips of the branches were frost-bit;-- but then, without any other frost or seemingly harsh weather, that same new growth dedided to die. Upon further investigation, that's when I realized the trunk was dead also. How could it have sprouted new growth on a dead trunk?????? This happened on 2 plants, photos of only the Ichandarin.

Your trees have definitely been frozen. Central Texas is not exactly the citrus belt. Where exactly in Central Texas? You will be lucky to have satsuma, the most cold hardy edible citrus, survive unless protected from ANY freeze lasting more than a few hours. Your limestone soil is not so great either. Citrus enjoys a soil on the acid side and 8+pH pretty much stops them from growing on most rootstocks.

Your tree is also very young likely the first winter and the smaller the tree the less cold hardy. And also sounds like the rootstock froze and the top survived, still a dead tree. Here in Beaumont, TX I had 6 small trees freeze to the ground. They are coming back from above the graft because I banked them(covered them) with dirt. Here, mature satsuma trees survived 8 hours of 19F weather without dropping a leaf. Oranges and grapefruit survived with 50% or more defoliation and some cracking of bark.

You definitely need to know the rootstock for such a cold place as Central Texas. It should be trifoliate or flying dragon to have a chance of surviving even with protection. It sounds like the rootstock was LESS hardy than the top, a very bad combination.

Lots of people have advertised a cold hardy citrus as "good to 20F" or even "survived 12F." Wouldn't that be nice if that told the whole story! That does not mean 20F for 24 hours. They usually leave out the "for a few hours" part of the statement. 20F for 24 hours will kill any citrus in Texas where the winters are not consistently cold. A few days of 80F followed by 24 hours of 20F will kill your citrus roots and all in Central Texas as well as Beaumont unless protected by covering/heating or banking the trunk with dirt to protect the graft.

The last time you fertilized is also important. Never fertilize after the 4th of July. You don't want your citrus tree growing in the fall/winter, you want it dormant with the sap in the ground.

Absolutely frozen, I have 16 dead above the graft. I have installed irrigation/freeze protection, a little too late but it is in now.

Thanks for the input. I realize I'm not in any kind of ideal spot for citrus, but I keep trying anyway. I think the main problem is I ended up with too many plants to try to protect for so many days - I about gave up. I'm NE of Austin, in Thrall 76578. Blackland/Clay here, and I attempt to provide good drainage.
My Satsuma mandarin (Miho) survived, unprotected on the west side of the house with no northern windblock--defoliated only, and already looking good again.
What really surprised me is my lemonquat didn't even flinch this year, looked great all winter. The only protection it had is being on the east side of the house, slightly less wind from the north.
Everything else(that didn't die) is going to need some good trimming once I definately know where.

I am glad that to know that the Lemonquat was hardy. Are you planning some sort of protection for next year.