Styling rock grown bonsai - ishizuki
This shape is to express the tree growing on rock and to make bonsai with this shape is really hard because the amount of the soil is limited because it needs to grow on rock compared to other bonsai styles.
This style of bonsai is beautiful but not recommended for beginners since it requires a lot of soil knowledge and techniques to grow bonsai.
Key points to make this shape
First, think about how the tree can get whatever it needs to grow such as water, nutrients. Basically there are two choices :
1. use some soils to attach the roots on the rock ( usually clay type soil such as peat, keto soil can be used )
2. put the rock on the soil and the roots crawling to the soil
In this case, the soils can cause unwanted conditions for bonsai. Bonsai trees usually like the soils with good drainage and aeration but since this style requires a clay type soil more than other soils in the soil mix you make, it can kill the ability of drainage and aeration.
In this case, the root may fail to suck whatever it needs to grow from the soil.
black pine, maple