I recently officiated a wedding (I also was a guest) where the couple was environmentally conscious. As the centerpiece on all the reception tables amongst the ribbons, flowers, and baubles were glass containers with tiny evergreen trees. There was a tree for each guest that sat at the table. The centerpieces were gorgeous, befitting the beauty of the wedding itself.
Please take it home and plant it in an appropriate spot, give it water as it settles in, then watch it grow. Five, ten, fifty years from now you can look at the giant tree it has become and remember that you got it at our wedding.
We hope you will enjoy our gift to you. We know the earth will benefit from the planting."
There were Yugo Pines, cypress, white pines, fir trees, junipers and more, a very nice selection. Each guest could select which tree they wanted to take home and plant.
If the tree type you wanted had already been selected you could trade with others or pick one that was left on another table.
What a nice wedding guest gift. Ten, fifteen and twenty years from that special day guests who took home a tree and planted it will still remember where it came from.
I checked on line (Googled live tree wedding favors) and came up with some sources.
Prices start at $1.25 and go up.