Something where I can speak from direct personal experience!
I built a couple of hugelbeds that I put in place despite the presence of a couple of young pines that had volunteered. They were perhaps three or four feet tall. The hugelbed came up about half the height of the trees.
In under two years both trees have died.
I am fine with that outcome, the trees were not in great spots, so now they are part of the hugelbed in a different way
