Creating Bonsai from Raw Stock

This past week’s Third Thursday class was quite a success and we had several smiling faces ready to learn. The topic was on how to take any raw stock that can be found at either a typical garden center or a pre-bonsai and prep for future training as a potential bonsai. Working with raw stock like this is good way to add more workable trees to your collection. Having more trees to experiment with is also a great way to try different techniques and seeing how they affect bonsai during each stage of development. Also, hunting for plants at garden centers trains your eye for material.

When looking for potential bonsai material at garden centers, there are a few considerations:

  • Does the plant appear to be healthy? Lift the plant gently from its container and inspect the root system.
  • Is there a noticeable nebari, or surface root flare? A workable nebari that leads into a tapering trunk is always a good springboard to start from.
  • Are there plenty of branches up the trunk of the plant to work with and make branch selection? Keep an eye out for oddly tapering branches from the trunk as the can present an unexpected challenge when it comes to design.
  • Is it a species that can naturally have a small leaf size, or can the leaves be reduced with techniques? This can be one of the biggest deciding factors when choosing plant stock for bonsai because you must consider if you will have to fight oversized foliage with the plant constantly.
  • Lastly, what are the required conditions for the care of the plant in question? Does this plant need full sun or dappled shade? How much water will it require and what balance of fertilizer is necessary for success?

I have always enjoyed taking trips down to the local garden center looking for plants that would be suitable, and over the years have made some great starter bonsai from them. While this is a good exercise for looking for material, a specialty bonsai nursery is the best place to look. The stock that the nursery has available have been hand selected for pre-bonsai, is already in good quality soil with fertilizer, and there is usually someone who works with the plants that can point you in the right direction based off your skill level.

Having reviewed with the class about what to look for in a pre-bonsai plant, a demonstration was given on repotting a garden center Buxus, or wintergreen boxwood. Buxus was chosen for the repotting since evergreens can recover well from summer dormancy root work. The Buxus presented a challenge due to a very fibrous root system. The fact that only 40% of the root mass could only be removed during this time of the year also limited the selection of containers. The decision was made that instead of forcing the tree into a shallow training pot, that the original garden center container was cut shorter and reused.

A critical aspect of the repotting process is to replace the original store-bought pine bark for good quality bonsai soil. Many garden centers use pine bark because it allows the plant to maintain moisture throughout packaging and its shelf-life. Once the plants are bought home, they are typically planted in a garden for landscaping purposes. However, we are making bonsai out of these plants, so we need to improve this growing medium for the health of the plant. The other purpose of repotting is to adjust the root ball from a vertical position to a more horizontal positioning to allow for adequate energy distribution and for container aesthetics.  

Another demonstration was given on a dwarf Acer palmatum, or Japanese maple, for the purpose of branch selection. A lucky door prize winner, Kirsten Pursifull, won this dwarf Acer palmatums to develop her skills on.

After the main part of the lecture and demonstrations ended, the floor was open to whom ever wanted to start working on trees they brought with them or bought at the nursery. A wide spectrum of species was worked on. David Barbay brought a false cypress to practice repotting on and Jacob Wade purchased an Acer buergerium (trident maple) as his first pre-bonsai and jumped right into branch selection and pinching off new shoots to promote back budding.

This was only part one of a beginner’s series of classes we will be providing. The proceeding classes will be built upon what was taught before and we hope to watch all our students progress and evolve their understanding of bonsai.