Hydrangea, also known as Ajisai, belongs to Hydrangea of Saxifragaceae. Hydrangea is white and plump, big and beautiful, and the color can be red or blue, which is pleasing to the eye. It is a common potted ornamental flower. Hydrangea was cultivated earlier in China, and it was planted in Jiangnan gardens built in Ming and Qing Dynasties. Parks built at the beginning of the 20th century are also inseparable from the arrangement of hydrangeas. Modern parks and scenic spots are planted in pieces to form a landscape.