I moved a small oak sapling to an indoor pot last year and intend to keep it as a bonsai project, the tree seems generally healthy and had one growth this season allready (it didnt lose all its leaves in winter though) (as you can see in the picture). I allready repotted it from a smaller container once and removed some of the roots and the main root when doing that (in hindsight I am not sure that was the best thing to do).
I am wondering if i can do something to make it branch out, as the tree is currently just growing vertically. Any care tips are also very welcome!
Thanks a lot, Thomas