RE: #BonsaiNews: I want to grow a bonsai forest [Looking for advice]
Usually a forest grows together, with the roots intertwining through the other roots. I think you are supposed to train the roots to grow like a single tree root ball mass.
When building on rock, usually the trees are wired in separately to their designed spaces, and can be repotted separately.
This is design choice you can make. Do you want to have a single root mass to train and let them compete with and support each other, or do you want to grow your trees in separate compartments to ensure the health of each tree's separate development?
In my saikei I'm choosing to let the trees grow together, and let some of the weakest trees die. The roots will be supported by a screen that runs across the bottom of the pot, which should aid in lifting the trees out all at once, without disrupting their arrangement.
You've given me a lot to think about - I am more concerned about the trees and their individual health. If planted together my concern would be that when re-potting comes, it would be difficult to remove them all together especially since I would love to try and get the roots to also grow above the surface somewhat however, I like the idea of including mesh below the surface which would definitely aid in removing them all at once.
I did not think about grafting the trees onto rocks though - that sounds like it could work much better and greatly increase the visual appeal. I really like this idea and I believe I will opt for this. Maybe I should shift away from a simple forest idea and create an entirely unique landscape from scratch for this. I can see myself breaking the bank on this project. I'm going to get to the drawing board and come up with a few ideas. Thanks for the feedback.