How did the custom of throwing hydrangeas come into being?

Throwing hydrangea is a traditional sports activity of Zhuang nationality in Xu Ge. Every year, on traditional festivals such as Spring Festival, March 3rd, Mid-Autumn Festival, the Zhuang people will hold songs. At the song festival, young men and women were invited to meet in the fields and by the river. They are divided into men and women. They keep a proper distance, sing to each other, express greetings with songs, and enhance understanding. Lyrics have a wide range of contents, involving ideals, feelings, farming and so on. The song has questions and answers, the voice is constantly fluctuating and the expression is beautiful. The girls couldn't help but pick up the delicate hydrangea in their hands and throw it at the right person. The young man caught the hydrangea quickly and accurately, appreciated it and threw it back to the girl.