If it's your only one it was probaby a good idea to remove some pups. How was the root developement on them and how big were they? Jeff Earl has said that it is the first to start growing in spring and does so about the same time as musa basjoo but I believe he's in zone 8 and"only" gets down to the mid 20's F in his local. Still I was thinking of taking one of mine and trying to do the same up here just for an experiment but, I have several ( That I'm tired of digging up
). Please keep us posted on this.