Young trees will be killed to the ground at winter temps of 25F here in California, and even mature trees have suffered major damage at 20F here in interior valleys of northern California, which is zone 9. I would plant them in containers and bring them inside in your area, or treat them as an annual...

You say 'killed to the ground,' will they come back from root?

Like I say, I saw the zone listings...so I'm warned. I guess I'll see what happens.

thanks,
tami