You can do the same in marbles, gravel, peat moss, fired clay [ lecca ] ................................
Remember it is the union of Bonsai pot and tree, with a decorative soil e.g 100 % round gravel.
How the shapes / textures / negative -positive spaces, masses interact.
Good Day
Anthony
* And you can even magnetically levitate them.
If one has gotten too bored lovingly growing the plants.
Teasing here.
Have a good chuckle.