I lived in Dallas and I can manage to prepare flowers for Ikebana lessons. However, they do not have as make kinds of flowers or branches as in Japan.
In Ikebana seasonality is one of a ley elements, so I miss some flowers and branches sometimes from season to season.
In the fall, Japanese pampas grass is my favorite. When I found them at a flower shop, I was really happy!!
For moon viewing, which is called Otukimi/ Tsukimi is the time we decorate Japanese pampas, rice dumplings to the moon. The dumpling is called Tsukimi Dango.月見団子.
What kind of flowers are typical for your in fall?