I have a Eucalyptus Silver Drop that I grew from seed last winter. I planted it outside this summer, and it did very well. I dug it up to prepare to bring it in, but last night, the temps dropped to -5C, and it looks like it sustained frost damage. From what I have read, this species is E. gunnii, and is supposed to be hardy to -15C. Do I have a different plant that can't tollerate frost, or what? Do I really have E. gunnii, and how hardy is it?