I am making hugel beds here in Wyoming. We are zone 3-4. It got to -38 here this winter a few mornings. On what side would you plant zone 5 fruit trees by the hugelkultur bed? It is on contour so runs east to west then wraps around to the south then back to the east..or will be that way when we get it done

Why I ask is: will the warmth of the south or east protected side, encourage the tree to break dormancy early and then get frosted? Or will the decomposition of the wood help that?
New to permaculture and all of this stuff but wow it rocks!
I will be doing a hands on class the end of April on it to introduce others to it.
Thanks everyone!