Zone 5 northeast USA has had an early winter in some places, getting slammed with many evenings in the 20s and a few even lower. Some snow but it's come and gone, eventually melting after a couple weeks. A warm spell has melted most snow recently and the ground is still soft, it didn't freeze deep yet.
Can a dormant hardwood tree be planted in the soil if it's not frozen? What if temperatures will drop below freezing the night or coming days after planting? I have some potted trees and spots ready to dig for them! Winter weather came early so I didn't plant them earlier in the fall.
My understanding is yes as long as the trees are totally dormant before transplanting. In terms of planting I've heard to pack the soil a little compressed and add lots of mulch on top to help prevent frost heave from throwing the tree back out from the ground!