Mizuyari is a Japanese word that means watering, the most important process to grow a bonsai tree. Water supply is essential for a bonsai tree that is grown in a limited space of a pot. Many people say it takes three years to attain the watering technique. There is no perfect manual for watering. Growers are required to pay full attention to various aspects, such as the season, weather, temperature, humidity, soil condition, and tree species.