reyderrs, my Autumn Moon has been in a 14"x14" wide X 17" deep pot for 3+ yrs. Current trunk diameter about 1 1/4" at 1 ' level and its about 5-6' tall. When I annually remove it from pot, there is no sign of roots on outside of soil. I am in zone 8b. The only problem I have had was top leaves/branches died due to lack of water, my fault.
The only possible problem I can think of is nights with negative temps. When living in zone 5a in Colorado, my temps would go to -18 f; my smoke bush was planted in the ground and it would freeze to ground killing all above the soil. It would then regrow in spring from the roots. I learned to protect the smoke bush by using plant blankets. If it was in a pot, I could have moved it into the garage that stayed above 32f.
Hope this helps.
