I've kept some in a pot. They do grow fast so I had to trim the roots every spring or fall. Worst case scenerio is to root a few stems if it gets to much to handle and get rid of the larger plant. Some of the ROS here are 15-20 years old and don't have that size. They are large though and have about 6in stems. It has been pruned back every year though.

One Question, why are they in pots? They sure are hardy enough to winter over as far as Michigan.

I'd like to plant one near the house, but I don't want to take the risk of the roots damaging the foundation. So I'm considering a very large pot instead.
~ freshair

I have them growing right next to the wall all around the house. 20 years ago I had NO idea what I planted...then I left and 2 years ago I came back.
So far..no problems. 2 are even on top of the septic tanks...no problems there yet either...knock on wood

Good luck