Tree transplant plugs over wintering

(Question)

hi just wondering if conifer tree transplantplugs will overwinter in a unheated hoop house in zone 7a Canada. Keep in mind the trees will still be in the 412 transplant tray and will be sitting above ground

(Answer)

From what I have read, conifers are often hardened against cold weather by a freezing process.  In the wild, the root structure would not be very deep and the soil would freeze around the roots.  Given that your seedlings are in a hoop house protected from the drying effects of the wind, they should survive and actually benefit from the freeze cycle.