Hello fellow bonsai enthousiasts,
I bought this Trident Maple in January this year, it was growing in the field at a local bonsai nursery. I noticed that the tree is growing vigorously and i was wondering how the roots were developing. As you can see in the pictures, it has put on a lot of new roots and they also are bound at the bottom (they have formed a layer of 1cm thick). I was wondering if a repot, with root pruning, in a bit shallower training box would be beneficial to the tree? I don’t want it to be root bound etc. If i want/need to repot, i would do this in the beginning of spring 2021 (march/april). Thank you!
Looking at the roots you could even leave it until 2022 to repot. As it came direct from a field it has loads of energy and as such you get coarser growth. If you want to start work on the tree you could easily repot next year.
It looks like the trunk is not very thick at this point so I would set the basic structure and keep it in this grow box. That will promote strong growth of your structural branches, some trunk thickening, and development of the nebari. You might even want to repot back into a similar grow box in 2022 after root cut back and arrangement to continue development of the nebari and any branch thickening that might still be needed.
The roots are doing great but I don’t think they are so bound that you need to repot now. You still need the roots to grow towards surface and the interior of the rootball.
Thank you for the replies. I will set the basic structure this year and keep it in the growing box until 2022 so the tree can, as suggested, thicken up and set the structure for the branches.