I feel confident at root pruning but I certainly am not in your League Ken.
I just know if I loop off the top it will be the end.
I nicked the stems to make it branch last year so I am getting more branches now. I picked these up in little 4" nursery pots years ago. I always killed the green one so I was taking a chance at keeping these alive and have been surprised how big they got from those little tiny pots.
In the one big pot is Ficus Burgundy Robusta, in the other pot I have two plants Ficus Elastica Belize and Fiscus Elastica Tricolor
