A well-structured inorganic particle allows for quick water drainage and allows fresh air to continuously penetrate the soil. A compacted and organic soil without these structures lacks aeration and drainage and this can lead to health problems in the roots of trees and cause them to rot completely. By varying the soil mixes to suit different bonsai tree species, the nutrients to be administered also vary. In fact, pines and junipers require much less water than other species, therefore, even the soil must adapt to their structural characteristics. Alternatively, bonsai especially those for flowering and fruiting have a need for water and at the same time an excellent water retention capacity. When mixing the soil, the ratio of water to drainage materials varies according to the tree it is intended for. If the quantity of grit is increased to the mixture, the soil becomes more and more draining and with high water holding capacity.

Organic soil mixes such as peat, leaves or bark are the building blocks for a standard soil. However the best mixes are complete when volcanic lava, lime and clay are added. These materials are more difficult to find but can still be found in garden centers, specific nurseries for bonsai, and in the case of some types of clay even in supermarkets and hardware stores. In past decades, Western bonsai enthusiasts tended to use organic mixtures with a large percentage of peat, bark and leaves mixed in for soil drainage. Over time, the better knowledge and understanding of the bonsai processing and production technique has increased and today, the use of simple organic materials does not favor the vigor and development of the tree. However, peat and other organic components of the soil have many disadvantages, including water retention which leads to soil rot, particularly during rainy periods in autumn, winter and spring. On the contrary, during periods with high temperatures, dry peat can prevent the normal flow of water by leaving dry spots in the areas adjacent to the roots of the bonsai. The only organic component that is always recommended to be used as part of a bonsai soil mix is ​​sifted bark compost; this in fact breaks slowly, maintaining its characteristics as a draining tool for a long time.

The advantage of inorganic materials is that they keep their structure alive for a long time without becoming pulp. In fact, they allow to conserve a certain amount of water and any excess is immediately expelled through the bottom of the soil. This is one of the ideal conditions for growing and growing a good bonsai in a healthy place. Among the best inorganic mixtures indicated for the cultivation of bonsai there are those of an industrial nature of Anglo-American origin, easily available in our garden centers. These products are of different caliber, already mixed properly and carefully studied in the most famous universities to give an excellent drainage to the plant, favoring as a basic component the clay which has always been considered one of the natural elements of the soil as an excellent and unparalleled drainage. To grow a bonsai in a healthy and luxuriant way as the Asian masters have always done, it is essential to choose or create the right soil.