Quote Originally Posted by Socrates View Post
Well when I go up to my families house up in Wisconsin I'm grabbing some rocks w/ lichen and/or moss or both (woot!). It's out in the country w/ no pesticides/herbicides or any other nasty chemicals.
That's what I do, it's all natural and looks great. The only thing you need to be careful of is certain kinds of wood. Johnny (sludgemunkey) wrote a great article on this subject.
http://www.caudata.org/cc/articles/wood.shtml