I have a beautiful ming aralia that is approximately 13 years old. It is getting quite large and the "branches" are getting heavy and sort of drooping down. There is not much new growth at the bottom either. I am wondering if I should be  "pruning" this back a bit or if it should be held up in a taller planter with some type bamboo stake?  It typically drops  a lot of leaves as winter approaches but this spring it has also lost more than normal.  Any help would be much appreciated.