I just finished re-potting a new bonsai. I think this is the best one I’ve ever done, so of course I have to share it here. the tree is a Montpelier Maple that I bought from a local nursery early this last summer. It was in a one gallon pot and intended as a young landscape tree. I think i paid under $20 for it. It was way too hot to transplant it so I trimmed it and I have been wire training it in it’s original pot for months. The weather here has only just cooled off enough for me to feel safe to re-pot it.

First thing was to carefully comb all the dirt out of the roots and trim them up just the way I wanted them.

exposed roots

Under the soil I found some really thick roots that are perfect for a root over rock style that I’ve always wanted to do. I trimmed the small roots off the higher thicker roots, effectively turning roots into trunk.

For years I haven’t realized just how important soil composition is when growing a bonsai. I guess I just thought i knew how to spot a good potting soil and that it would be good enough. I’m only just starting to realize that I can’t use any potting soil at all. Nobody sells the right composition so I had to make my own.

since I’m planting a maple, I had to go with 1/3 organic material and 2/3 inorganic material (rock). The other consideration that is very important is particle size. So I bought a bag of regular potting soil for the organic material, a bag of pumice, a bag of some sort of dark lava rock, and a bag of vermiculite. I bought a soil sifter with 1/8 inch screen to sift out all particles larger than 1/8 of an inch. Then I made another sifter with regular window screen to sift out all particles smaller than 1/32 of an inch. I sifted each material separately then mixed them in the correct ratios. I’m sure I’ll fiddle with the recipe a bit for future projects, but i believe i now have a near-perfect soil.
sifting soil

I then selected a rock that seemed to fit my tree, and planted it. The tree ended up a few inches taller than it would have been since I raised it out of the soil and turned some roots into trunk.

root over rock

I really wish I had a digital camera so i could represent this tree better. It turned out even better than I had hoped. If you look closely you can see the wires all over the trunk and branches. They will come off in the spring and I will only be training it through trimming after that.

Maple