@brezofleur- I have been living on pintrests, lol. That's where I got a lot of good ideas.
The problem with using things and then giving them to the guests is 90% of guests are flying in from out of town so having a plant to carry would be hard.
We were thinking for favors- of doing mini pots and just putting flower seeds in them along with a "pledge to the planet" which will be like a recycling or eco friendly thing the person chooses to do for a whole year. That way its easy to transport and eco-friendly. I could always donate fake flowers to nursing homes too