This July article got me thinking...
Elon wanted to send a garden to mars which lead to him starting SpaceX. Mars One is betting on a lander from SpaceX on its mission critical path. They are inviting teams from any university around the world to submit a payload... Which might be a garden. Sorry Elon, you're not a university.
If I could submit a proposal it would be a large variety of packets of seeds that produce edible vegetation along with vitamin pills waiting for any human expedition to come along.
I guarantee this would clarify space property law for any moron that would like to argue about it.