When/how to prune a baby Japanese maple?
I just transplanted a 4-ft. tall Japanese maple that started as a volunteer in my yard. I potted it up when it was tiny (two years ago) and just now moved it into a 5-gallon pot. It is growing in a shady area (underneath a canopy of its parents) and has just one central leader and lots of wire-thin branches. It was growing nearly horizontal, so I staked it to grow upright, but now I kind of miss the old shape--it looks really odd now, growing straight up with lots of little branches from one straight trunk--almost like a Japanese maple Christmas tree! When and how do I prune it so it becomes a multitrunked tree (all of the other Japanese maples in my yard are multitrunked), or at least prune off the bottom branches?