Neil, did you ever get an answer to your question? It won't flower as well in the pot if at all. The real danger is it may escape out the bottom of the pot and through the space in the pavers and show up 20 or 30 feet away before you realize it!!! I've got 2 at my new home that were planted last year(2009) I uprooted what I could spring of 2010, and by the fall they were coming back up as if they were never removed. Had I known they were there I may seriously have considered not buying this home. I was willing to put up with trying to erradicate poison ivy before dealing with campsis radicans again!