RE: Tree bark growth question
If the bark is growing around the steps they have been there for awhile. As for how long it's anyones guess. And, depends on tree species, soil fertility, competition, droughts, etc. Get the point?
I've had folding tree steps in a white ash tree at the edge of my field for five years now and the steps are beginning to turn upward at about a 60 degree angle. The good thing about these types of steps is that you can fold them and remove them while the non-folding steps are almost impossible to remove without damaging the tree once the bark grows around them. I will take them out after this year and move them a few inches to prevent them from turning upward.