I grow catnip, which I dry and use to make cat toys for the shelter. Of course, our gang gets to enjoy some too. This year, my 'nip isn't growing as vigorously (our part of the state is in a drought). However, I discovered a large amount growing in our alley, a few houses down.
The area isn't maintained very well, so I figured the neighbors wouldn't mind if I took some (in fact, I'm probably doing them a favor, LOL).