Uetsuchi is soil used when a bonsai tree is planted in a pot. Generally, it is called yodo (soil for horticulture), which is considered separate from gorotsuchi (the largest grain in akatsuchi soil which is used at the bottom of the pot for good drainage) and kesho tsuchi (silver white sand used as a top-dressing). Many times sand and soil are mixed and used in ratios according to the need of varieties of trees. The soil is rich in keeping water and good in draining water and air circulation. Particles not easy to crumble are considered most suitable for bonsai planting. Particles measuring 1 millimeter to 3 millimeters are chiefly used for uetsuchi, while gorotsuchi is used at the bottom of the pot and tiny grains about one-third the size of uetsuchi is used on the surface of the pot.

translated by Kyodo News