Here is a top producing vft in my collection (Pete's Giant) during very harsh dormant conditions. Now I mean constant temps in the teens for days, up to fourty in the garage the next unfreezing all the plants, then boom another hard freeze and this goes on and on and has happened at least four or five times already! Who says a vft can't take harsh freezes! They seem to be looking better then the experiment plants that have dormacy in the fridge right now! [img]http://www.**********.com/iB_html/non-cgi/emoticons/new/smile_m_32.gif[/img]
The main thing is to MAKE sure that the vft is in decent shape with at least decent root system (ones with no roots will suffer some what if they were unhealthy to begin with), and that they are covered in something to protect them from the wind frost during extreme freezing temps. Other then that I don't think that the temps affect them all too much. Although there are some types that don't take freezing temps good. The only one I'd watch out for is Dingly's Giant (Which I just lost because I forgot to put the pot back with the others) and a few seedling here and there which weren't too healthy to begin with. Some other weak t/c mutation clones might be in this group as well.
For the weaker plants this is where fridge dormacy helps. It IMO isn't nearly as good as other types of dormacy's but since it isn't as harsh the weaker plants can make it through dormacy fine until the growing season.
Well, here is Pete's Giant in dormacy-
The pic of the whole pot, most have 1" traps
And here is Pete's Giant with traps almost up to 1.5" in deep dormacy. I could only imagine the traps this summer