Mizunuke
Water drainage. It refers to drainage of water from the bottom of a pot. It is also called ”mizuhake.” Not only water but oxygen must be supplied to tree roots to help them grow. After moisture between soil particles dries up, fresh air comes in and helps activate hairy roots smoothly. So, growers need to select proper potting composts that drain water smoothly and also should carefully study the placement, number and size of holes in the bottom of a pot.
translated by Kyodo News