Matt Hughes i like to grow tiny trees and tinker on stuff

Started training some bonsai

This weekend I finally got started on creating my own bonsai from plain old shrubs from Home Depot. It was pretty involved, since I sifted and mixed my own bonsai soil, built some training boxes, and re-potted the trees.

Bonsai Soil

Bonsai soil mixes are a very divisive subject, and I've come across about countless recipes and recommendations. One thing that everyone can agree on is this: the three main components of bonsai soil.

  1. Porous material (akadama, pumice, Turface, diatomaceous earth)
  2. Organic material (pine bark, orchid bark)
  3. Grit (gravel, sand)

Akadama is the classic bonsai soil component, but it's definitely pricey! I searched for a while online for a more affordable substitute, and found out about Turface and diatomaceous earth. Opinions on Turface range anywhere from great soil component to never plant your trees in this garbage.

I figured for a few shrubs I got from Home Depot, I would use more affordable soil components. I finally decided on 1/3 NAPA oil dry (diatomaceous earth), 1/3 chicken grit, and 1/3 pine bark for my soil mixture. From the thousand different bonsai soil articles I read, this seemed to be a good all-around soil mix for me.

I wasn't sure where to get find Turface locally, so I used diatomaceous earth from NAPA instead. The chicken grit (crushed granite) came from a local feed store, and the pine bark mulch came from from Home Depot.

Bonsai soil seives
Bonsai soil seives
Bonsai soil mix

Training Boxes

Training pots or boxes are used to transition a "normal" plant's growth into that of a bonsai. These pots are deeper than normal bonsai pots, but wider and shallower than regular plant pots. I didn't want to drive all the way out to my favorite bonsai nursery to get training pots, so I decided to build some training boxes from lumber.

I couldn't really find much in the way of specs for these, so I just came up with my own. I went for 7"x7" square, and 4" deep. I built them out of regular pine 2x6s and 2x4s, because I wasn't sure if the chemicals from treated lumber would be safe for the trees. I drilled two 1" drainage holes in the bottom, and covered them with bonsai mesh.

Bonsai training box Bonsai training box - bottom
Bonsai training box - soil mesh over drainage holes Bonsai training box - wire holding soil mesh in place

Here are the materials needed for one box:

  • 2 - 2x6, 10" long
  • 2 - 2x6, 7" long
  • 2 - 2x4, 7" long
  • 2 - 1x2, 10" long
  • 8d common nails
  • 1 1/4" wire nails

Next time I build these, I will probably build the bottoms differently: maybe a 2x4 in the middle and 2 2x2s on each side. Trying to use a spade drill bit in the middle of two boards was really difficult, and tore the wood up pretty badly. My spade bit took quite a beating as well.

Potting the Trees

I potted and styled three trees: a Japanese holly, a white azalea, and a burning bush. Unfortunately, I didn't get any "in progress" pictures of my Japanese holly.

Japanese Holly

Japanese holly pre-bonsai



Azalea roots

Azalea roots

Azalea pre-bonsai

Burning bush

Burning bush

Burning bush roots

Burning bush roots

Burning bush pre-bonsai

A big thanks to my bonsai apprentive, Stevie, for his help and companionship with this project!

My bonsai apprentice, Stevie