I just thought that I'd share a picture of a neglected and abused door mat that has been rained on for the past two years and which hasn't been walked on. The mat is one of those types with a brown, stiff, hair like top. If I would have tried to do this intentionally it never would have happened. We live in Pennsylvania and it's rained so much in the last two years that moss and mold grow where they've never grown before. Probably in some parts of the country this happens all of the time.
I have the same doormat I believe. And yes, one year it looked similar. But as we used the entrance to that door regularly, the moss was of a different kind and shorter. Still, it had enough muck and moisture (and shade) to have a nice green shade!
I am only one, but still I am one. I cannot do everything, but still I can do something; and because I cannot do everything, I will not refuse to do something that I can do. (E.E.Hale)
Acetylsalicylic acid is aspirin. This could be handy too:
Greenhouse of the Future ebook - now free for a while