Bar / Bat Mitzvah Planning with Doctor Simcha

I can't tell how surprised I was reading that your son is going to have a green Bar Mitzvah. My son also wants although I am not sure if he will stick with it by the time I start planning (I hope he will). When my son wanted to do it the first thing that came to my mind is that more important than doing "all green" is actually try to get all guests involved and conscious about. I don't how are you doing so far (I would love to hear about!) but maybe you'd like to consider giving seeds or something similar for the guests favors. Even letting them know that if they can't plant at home then they could find a park or organization that allows them to do it or even another person so you know that all seeds are planted somewhere.
If you can post a picture or let us know you family's experience I would appreciate a lot.
Mazal Tov!