Rock planting root maintenance?

How do you maintain the roots of trees/plants in rock planting? I am talking about trees planted in crevices (and roots are contained therein) that are impossible to remove after they are settled without destroying the tree or the rock.

Note that this is not ROR where the roots can be maintained at the bottom (potted portion).

Just wondering.

Just add soil on top of the roots because if the rock is at all porous the roots have gone into the rock itself.

These are not "forever plantings."

As above, try to change soil in a top dressing way and maintain balanced feeding. Use decent soil components that will hold together for 10 years as well.

Normally the rocks break after a while so that is the time to rebuild the composition (or the tree dies off) - in much the same way tridents Over rock eventually pass their best - once the roots thicken and fuse so much the rock is hidden from view the tree has lost the balance it had in its peak. Avoid big trees on little rocks if you can.

Thanks guys! Not planning on making one (yet)...just curious.