Eucalyptus Species, Cider Gum, Gunnii

I planted two Eucalyptus Gunnii. I live in western Oregon, probably zone 8.

Both grew, initially. After 4 years and a cold...Read More winter, one failed. Like the writer from Bulgaria, I cut it back and it re-sprouted. Two winters later it again seemed to have died. No new growth is visible.

But the 2nd Eucalyptus Gunnii showed no stress in any of the years and is now probably 12' high.

There is a hybrid called "Silver Drop" and the tag says it is not winter hardy. It is described as a "Dwarf form. Grows 20'+ tall." I like the tree so I tried planting two more.

Two reports for the winter of 2011/2012:
Sofia, 2300 feet AMSL, 6b
After becoming a substantial tree with a nice trunk, E.g...Read Moreunnii was planted into the ground, grew well through summer, and had to face the worst winter I have seen during my lifetime in Bulgaria. Knee-deep snow cover stayed on the ground for full three months, providing an excellent insulation against cold. Winter low was -7 degrees Fahrenheit. After cutting it into healthy wood a couple of inches above ground in late winter, I can now report that the tree is regrowing from the trunk in multiple places. Another plant, a small seedling, which was completely buried under snow, is preparing to regrow too. This is a definite success.
Krapets, Bulgaria, sea level, 7b/8a
Two small seedlings were planted into the ground in spring 2011. They grew much slower than the one in Sofia, barely reaching over 10 inches high. No snow lay on the ground during the worst frosts. Winter low was +2 degrees Fahrenheit. The result is a couple of fallen leaves from one seedling, and an entirely healthy second seedling. Only noteworthy change was the burgundy color of the foliage. Not knowing this is normal, I pruned the two seedlings, only to find that they were completely flexible and juicy, leaves and stems. This is another success. They are regrowing right now.
My conclusion is that this is an immensely hardy tree.