Yes, my bonsai collection of trees seems to be growing faster than the tree themselves. Last count, I have over 30 trees growing under my care.
In this article, I am featuring my Chinese Elm tree. In October, I took photos of the work I am presenting here.
Below, I'll detail the progress I made to the tree by improving the soil. Some explanation of the roots and type of soil will also be provided.
A wonderful starter tree to grow as a bonsai. A favorite bonsai tree because the leaves are small, and it grows quickly. Cuttings can be taken from the roots and branches to propagate new trees.
Branches have to be trained with wire when they are young, because the wood is not very flexible and it will harden within a few weeks.
Examining the Surface
The soil is deeply coated with moss. Not only has the top of the soil mounded quite a bit, but the edges are also mounding over the rim of the pot.
The moss is retaining lots of moisture which is helping to support roots underneath. This is good.
The roots in the center of the pot will not have access to fresh water and air, because the moss is too thick.
The decision is made to remove the moss, because it is creating deeper problems, and only helping on the surface.
(Sort of like the last steem hard fork, but we can rant out that in the comments. Ahem!)
Next, I'll be peeling away these upper layers of moss to examine the condition of the roots below the surface.
The roots along the soil surface are thread thin. They appear to be healthy blond in color, and should not be disturbed too much.
The large decorative basalt rock seems to have slid away from the aerial roots. Once I remove the remaining moss, I can slide this rock back underneath so it looks more strongly nestled inside the roots.
Large decorate rocks serve no major functional purpose to improve the roots of the bonsai tree. They can be used to improve the aesthetic shape of the tree and pot together. However, I have noticed that large rocks can benefit a tree. It can prevent moss from spreading on the surface underneath, retain moisture, channel rainwater, and provide a habitat for many micro-organisms good for soil health.
Many people will incorporate a decorate rock feature to help the tree design to tell a story. Perhaps to symbolize the strength of the tree as it had to grow over difficult terrain, and perhaps to display the type of mountain region it came from.
Roots can sometimes become a major design feature in a bonsai tree when they are long and visible over the soil and rock surface. Ideally open space under the roots should be filled in as much as possible, to hold the tree more tightly in place.
I have not done a very good job with this. In years time, I am hoping the top roots will thicken and conform to the shape of the rock, until it constricts it and eventually looks strong. A better strategy is to find a new rock that will fit more closely with the shape of the root.
With a hand rake, I scraped off as much moss as possible.
Often times little broken pieces of moss were slipping into the rocky bits underneath. I painstakingly carved out all the problematic soil by hand in some cases. A chopstick or toothpick can be helpful tools. Even an old toothbrush can be a good way to brush out the smaller moss bits.
Additionally I removed the ugly green wire that was circling under the bottom of the pot. That wire was there initially to hold the tree firmly in the pot. I believe this pot is deep enough to hold the tree firmly down on its own now.
The moss often clumps into the rocky soil. It forms a peat and clay mush. Really, it is better to remove the entire cluster when it gets that bad.
Roots will eventually suffocate and drown when the soil is unable to dry out in this sheet of mossy mud.
Picking up the Pieces
For the next hour, I worked by hand. Inside those mossy soil clusters, I noticed quite a bit of healthy soil still existed.
Especially the tan colored pieces, these are Akadama clay, a valuable soil additive that is made only in Japan. The clay has a unique property because it has pourous holes, and it shatters under pressure due to the volcanic heat that turned it into a half-glass state.
Also the red lava rock is hard for me to find as a local resource. I work slowly to salvage as much clean soil as possible to reuse.
Using the clean soil, mostly lava rock, akadama, and pumice gravel, I have covered the surface roots completely. Only the aerial roots growing over the large rock are allowed to remain exposed to the air and sunlight.
The soil line has been lowered back down to an appropriate level.
Rainwater will no longer spill over the edge of the pot. The rocky soil will allow for quick drainage, so water will not puddle on top.
And now the work is complete. The tree is looking wonderful again.
'Tis a shame, it will be tucked away from sight for the long winter months.
At least it can live on here in photographs.
Find me on discord and chat with other tree growers, bonsai enthusiasts, and gardeners. We have quite a few accredited experts filling out our ranks, and a helpful Spanish-speaking community.