hi mel thats a nice tree you got there
i have found with mine as soon as they get put into a pot they virtually stop growing. i have my biggest one in a grow box and it is going well. i will fully develop it in the grow box before it goes into the pot, i beleive thats the only way to get them to be where you want. i have also noticed they hate there roots being disturbed, my two little ones nearly threw every branch they had when i potted them up, my plan with the big one is to slowly reduce the rootball. the grow box is larger in a horizontal area, but reasonably shallow, so i only need to reduce the horizontal plane of the roots
SHOHIN YAKUZA!!!
taking the top half of trees of since 2005!
and growing trees for the future generations! 50+ year plans