Cold Tolerance after 2025 Freeze

[countryboy1981]

Our area got down to 10/11 degrees this past winter with a foot of snow.  Trees are starting to recover now with the warm weather.  I banked soil around all of my trees to protect the graft line, however this did not save all of them it appears.  There is a lot of disparity from conventional wisdom as to what survived and what did not.  For example, I had a Juanita tangerine that appears dead as a doornail but two seed grown white duncan grapefruit trees that appear to only have sustained damage to the newest growth of the branches and defoliation.  The grapefruit trees for the most part are regrowing from where they left off last year.  I had a washington nvael that was several years older most likely on carrizo rootstock that appears to be complete toast and a glen navel on rubidoux that is sprouting above the soil banked area.

[Galatians522]

That is interesting. They say the level if dormancy is a major factor. More water in the tree = greater damage. Sometimes trees in PT will leaf earlier in the spring and recieve worse damage than a tree on Sour orange for example.

[1rainman]

That is what I would expect. Grapefruit is more cold tolerant than oranges or tangerines. Though the size of the tree is a factor too.

[gumbo2go]

For my citrus in Zone 9a/south La. I suffered losses of older satsuma trees (20+ yrs) and a navel orange (3 yrs) tree too. Another owari satsuma tree was heavily damaged but pulled thru.  My older loquat trees were burned back also.  Several fig trees were burned back to the ground.  Slow recovery this year.
  Mother nature is cruel sometimes! 

[tedburn]

For my experience
1. Rootstock is very important for cold hardiness
    (Poncirus is best)
2. Cold hardiness of grafted variety
3. Individual health status of rootstock and graft
.....
- Carizzo is not very cold hardy
- I guess the sometimes reported cold hardiness of
   Juanita is not existing. My Satsuma Collot on
    Poncirus froze down 5cm over grafting point
     at -9 °C but resprouted.

[countryboy1981]

It was a weird oitcome to say the least.  One of my fig trees was severely damaged but my two seed grown grapefruits were unfazed other than leaf damage at 10 degrees.  My owari satsuma which has been in the ground for nearly 10 years sustained way more damage than those 2 grapefruit trees.