Kanumatsuchi
This is a kind of soil for bonsai, which is a very light and porous rock of volcanic andesite quality and a substance that erupted ? years ago from the central crater of Mt. Akagi in Gunma Prefecture. It is accumulated in areas from Tochigi Prefecture to the seashore of Ibaraki Prefecture. The name Kanumatsuchi soil is named after Kanuma in central Tochigi Prefecture because it is a region where thick layered rocks are found. There are countless numbers of capillary holes on the surface of the grains. Since they are 2 to 3 times stronger in their ability to absorb air and water than the soil of cultivated land, they are superb for air permeability and drainage capabilities.
translated by Kyodo News