This is what can happen when you have a great rock and excellent plant material to work with (a little skill doesn’t hurt either). It’s by Norboru Kaneko, from our Masters’ Series Juniper book.
Needle junipers and companions growing on a rock. Like the photo just above, this one is by Norboru Kaneko and also from our Masters’ Series Juniper book. Given what we’ve seen so far, it’s safe to say that Mr Kaneko has achieved a degree of mastery when it comes to root-on-rock bonsai.
With bonsai, it's usually the tree that dominates, even though the pot, (stone, slab or whatever) is considered a critical part of the whole. In this case however, you might decide that it’s the rock that dominates and elevates the planting from very good to extraordinary. The tree is a Japanese quince (Chaenomeles japonica). The tree, rock and moss belong to David Benavente.
Here's an equally impressive and improbable Benavente planting. The main tree seems so relaxed and natural given its precarious position. It's a Scot's pine (Pinus sylvestris) and the others are Japanese quince (Chaenomeles japonica). As with the planting above, there are also ferns and moss. I'll guess the convex slab is man made.
A planting by Marc Noelanders. No mention is made of the type tree or what the rock is made of.
Three robust Shimpaku junipers on a stupendous rock. We’ve shown this one more than once, but it’s good enough for at least a fourth or fifth encore. From the Omiya Bonsai Museum.
Kimura rocks! I don’t think it’s a good idea to feature a bunch of root-on-rock plantings without at least a quick visit to Masahiko Kimura (aka the Magician), the grand master of root-on-rock plantings and almost anything to do with bonsai innovation. The photo is from a facebook posting by Alejandro Sartori that he took during a visit to Kimura’s nursery. The trees are Shimpaku junipers.
Another root-on-rock by the Magician that was taken by Alejandro Sartori. It looks like the trees might be Hinoki (Cham. obtusa), a tree often used by Kimura for rock plantings.
Beyond bonsai… Here’s an unusual and quite compelling rock planting by Colin Lewis. It’s hard to tell, but it’s likely that some of the roots have found their way down into the soil in the pot via the mossy channels you can see, which might make this one a combo root-on and root-over.