Kansui is a Japanese term for watering of plants, especially bonsai. It is also called mizukake, mizukure or mizuyari. Watering is an essential skill for bonsai care, as it replenishes the water that is lost from the soil and the leaves due to evaporation and transpiration. Watering also helps to flush out excess salts and fertilizers from the soil, and to maintain a healthy balance of moisture and air in the root zone.
Watering bonsai requires attention to the type, size, shape and material of the pot, the type, quality and composition of the soil, the species, age and health of the tree, the season, weather and climate conditions, and the location and environment of the bonsai. There is no fixed rule or schedule for watering bonsai, as each tree and situation is different. The best way to determine when to water is to check the soil moisture by feeling it with a finger or using a moisture meter. The soil should be slightly moist, but not wet or dry.
Watering bonsai should be done with a gentle spray nozzle or a watering can with a fine rose attachment. The water should be at room temperature or slightly warmer, and free of chlorine and other chemicals. The water should be applied evenly over the entire surface of the soil, until it drains out of the holes at the bottom of the pot. The excess water should be removed from the tray or saucer under the pot, to prevent root rot. Watering should be done in the morning or evening, avoiding the hottest part of the day.
Watering bonsai is not only a practical task, but also an artistic one. It is a way of communicating with the tree, observing its condition and needs, and creating a harmonious relationship between the tree, the pot and the environment. Watering bonsai is also a way of expressing one's appreciation and respect for nature and its beauty.