My own explanation was lacking, so I found this article:
Homecoming Mums: The Tradition
Chrysanthemums have long been the quintessential Fall flower, so it's not surprising that they quickly became associated with the quintessential Fall sport - football. In the earliest pictures of college football games, you can pick out the mum corsages worn by the young women in the stands.
Since everything grows big in Texas, it's also not surprising that the Lone Star State is credited with developing the more elaborate corsages known as homecoming mums.
So now that you Non-Texans know a little bit about a Homecoming mum, I thought that I would share pictures of my daughter’s homecoming mum that I made her. My daughter is now in intermediate school and they all wear homecoming mums to support the high school Football team. So of course I had to make her one. Since she is only in intermediate school I made it smaller then I would of if she was in high school.
I love the memories that I now have from my Homecoming experiences and hope that she will too!
The Traviling Junkies