After about 20 years each one of those will become a stem like your big one and you will have a multi-
trunked tree like in the photo above from Lin.
Out in the wild, these things will eventually become huge. Mine is now 40 years old and is getting to the
point where it is really hard getting it inside for the winter. One more year and it won't go out the door any longer.
I so wish I could find it a new home!
