Making a Bonsai Pot from a Rock

As I get into the art of bonsai, very quickly I learned that it's not just about the tree, it's about the pot too. Many really cool works have fascinating pots. So, I had the inspiration to use an actual rock as a pot. While not technically a bonsai, there is this little tree in Colorado that inspires me because it's been there for over a decade, and it always strikes me as such a difficult existence.

Natural Colorado Tree

Yeah, that's definitely my favorite tree in Colorado. So using that as inspiration, last month while out near an alpine lake, my fiancé and I picked up two rocks, and I proceeded to make them into pots. 

Two Colorado rocks about an hour into drilling.

 

Same rocks viewed from the top down.

Both rocks had some natural features that already lent themselves to being a pot. I used a series of drill bits, but of course the rock was wearing through drill bits pretty fast. Since the concrete drill bit I bought was wearing the least, I ended up using that 1/2" bit the most. The goal for both rocks was to leave the outer surface as undisturbed and natural looking as possible. That meant leaving the edges in the two rocks above untouched. Then drilling a series of holes to try and enlarge the volume available for roots and dirt. I'll call it rock One on the right and rock Two on the left, sort of triangular shaped. I was routinely spraying some water on the rocks as I drilled for two reasons, one to cool down the drill bit and extend the life of the bits. And two as the rock powder would accumulate in the hole it was hard to see exactly where I was drilling, and if I was hitting any new air pockets, so I would wash out the dust.

Method of Drilling

As you can see in the picture above on rock Two I drilled into the rock, but left the edges of the original hole in tact. Both rocks had a number of holes in them already, and as I drilled I would hit more air pockets and be able to lightly pry on the drill bit to try and expand those natural air pockets and remove the edges of each pocket to make the volume larger. I then used a small drill bit, about 3/32" or even 1/16" in some of the natural pockets on the bottom of each rock to make a drainage passage in both rocks. Many bonsais are susceptible to root rot and having good drainage is a necessity. I've made the self imposed rule that all the water has to drain from the rocks in their nominal orientation, any pockets of water that don't drain could lead to problems.

Rock One Complete!

I finished rock One and you can see the drain hole in the center. Getting to this point took about three hours of drilling time split between the two rocks. This is going to get an indoor jade plant my fiancé has been growing for several years, and I'll update when I have pictures. Rock two is still not done, I think that it might not get a tree until 2023 because I don't want to transplant what will probably be an outdoor plant going into the winter. Especially such a small root system that is sure to be more fragile than a tree with more roots.

That's all for today! Research question for another day, since I expect most of my bonsais to be outdoor plants, will I need to get a cold frame to keep them at least a little warm in the winter?