Repotting Bonsai Trees

I have to pass on the Iron Curtain series this weekend, because my mind and my hands are now fully occupied by work that won’t wait – repotting my trees. I only have this weekend for the deciduous trees and next weekend for the conifers, because after that the trees would be too grown and I would not be able to touch them without risking they die as a result. Which I do not want.

Currently my trees are more about quantity than about quality, because creating high quality bonsai takes time and I am only doing it for twenty five years. The plan is to build up stock now and refine it when I retire. Growing bonsai trees is not something for the impatient. But I have some medium to good quality ones already and I will share pictures. (I also have trouble getting my hands on quality bonsai pots, because they are not sold anywhere near and I am reluctant to buy them over the internet).

Here is a glimpse into the work that I am currently doing:

SandIt starts with buying a load of coarse sand and spreading it out to dry in the sun. That does not need to be done, strictly speaking, but I find it easier to work with dry substrate so I try to dry it as much as possible. Another ingredience to the sand is high-quality soil or compost, sieved through a 5 mm mesh and also dried if possible. And last ingredience is peat or some suitable substitute, like shredded old leaves and moss  and twigs, or maybe even saw dust. The organic material is there mostly to hold moisture and stop the substrate from clumping.


Mixing substrateNext step is mixing up the substrate. Because I have a lot of trees and other potted plants, this used to be the most time consuming and tiring part, taking up hours of hard work. Nowadays I am doing it in  a concrete mixer. A great saving of time and strength, I do not understand how I could manage without it. I was younger, healthier and I had less money but more time on my hands, so there’s that.


Various pots and bowls for bonsai trees.Whilst I am mixing suitable ammount of substrate, lets say 100 liters or so for starters, I also have to scrub and disinfect all the pots and bowls that are currently not in use. That is, I take them out, rinse them with boiling water and let them dry in the sun. That seems enough, I never had problem with fungal infections or rotting roots. I do not have enough pots to replant all trees at once, so I have to repeat this process multiple times as pots are emptied.


When the pots are ready and the substrate mixed, it is time to take out my most important tool case. Have fun trying to spot all the tools that are in it. All are used for tree care. And just in case someone can decipher the writing on that lid in top left corner – that is not actual mustard, just the cup in which once was mustard. Now it is full of charcoal to treat big cuts on roots.

Tool box for bonsai trees.


  1. Nightjar says

    Oh, I love bonsai trees, but I have long decided that it simply isn’t for me, I’m not patient enough for that. I really admire people who are. Looking forward to photos of your trees!

  2. jazzlet says

    I’m with Nightjar on bonsai trees, I love them but do not have the patience to even look after a boughten one properly. I too look forward to photos of your trees Charly.

  3. kestrel says

    This will be fascinating. I have always wondered how this was done. I see a brush, which I am guessing is used to paint tar or something onto a freshly cut place, to seal it up sort of like a bandage? When I’m taking care of the orchard I have to do that, except we found some that comes in a spray bottle. It’s true that you can accidentally spray other things if there is any wind at all when you use it, but as long as you are careful about that, it works well.

  4. says

    That brush is in fact for carefully cleaning bark, lichen and moss from dirt and fallen needles. This must be done very carefully, because the bark an lichen can be easily damaged but they are a necessary features of a good bonsai -- they give it the proper aged looks.

    Freshly cut surfaces on a bonsai are usually very small, so I coat them with balsam using an old pedicure nails cleaner. As with many other things, when I started I had almost no money so I have bought two professional bonsai cutting pliers but all the rest of my tools are repurposed ordinary things and tools. They do the job, but they do not look as fancy as japanese-made tools of course.

    I just repotted about 30 trees this weekend, and I have still 60 to go next weekend. And after that all the indoor trees and plants.

    I love this but I wish I had a good weather once again when I have a week of, and not afterwards or before, as has been the rule about the last ten years.

  5. voyager says

    Wow Charly, that was really interesting. I’ve always thought bonsai beautiful. I’m looking forward to seeing and learning more.

  6. Ice Swimmer says

    That’s a large scale operation. I’ve heard that growing bonsai takes skill and effort, but it’s interesting to see just what is actually done, with what kind of tools and what the substrate consists of.

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