BunjinEnt

Second,

Soil:

General rule of thumb soil mix for most species:

1 part turface
1 part granite grit
1 part soil conditioner

Some benefits and reasons for fast draining soil are:
1. Most plants will get root rot if roots are sitting in water.
2. While water is going in, it is also pulling in Oxygen and Nitrogen to roots.
3. As potting a plant is an artificial environment we need to ensure plants get what they need as far as nutrition.
a. We can send through more nutrients without risk of burning roots due to mineral build up.
b. We wire trees into pots because we remove tap and other structural roots and we want to stimulate the growth of fiberous feeder roots. Open free draining soil facilitates this. (I will not explain this process here. It is beyond the scope of this instruction. You can find the biology of this in other threads on this site.)
4. That said, we adjust the soil components based on the need to retain water based on species, environment and skill level of the Bonsai-ist.

Judging from your location and the species you are working with there should be no real reason to change the soil components listed above. It is all about the watering and our next topic: Light.

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