The primary purpose of fertilization is to make the various elements in the right proportions in the exact times and modes, to ensure the best development of bonsai. Hanagokoro and aburakasu are organic fertilizers of Japanese origin, the first suitable for outdoor bonsai, the second to the interior bonsai. In addition to solid fertilizers, the Bonsan Line offers a range of products specially designed to meet the various bonsai requirements, from organic fertilizer fertilizer to the one enriched with Vitamin B. Another basic element for bonsai is the earth: as the roots grow in the limited space of a jar this must have optimal characteristics for the well-being of the roots. In particular, it must be able to retain enough water and nutrients (water retention) to absorb the roots and at the same time provide enough oxygen for roots (drainage). The choice of the ideal soil contributes to the species, maturity of the tree, the shape of the vase, the cultivation conditions, and so on. The land, which can be mixed or pure, is best known for bonsai: akadama, kanuma, ready ground, ketotsuchi, pozzolan, gravel and sand.