We live about 300 kilometers to the north of the swamplands so fondly described by AareneX…it is even wetter here, with fewer annual hours of sunshine. It is a simple fact of life that outdoor surfaces get covered in moss…houses, fences, trees, sidewalks, decks…anything left to its own devices will eventually succumb to the stuff,. When we got home from Australia I took one look at the deck and decided to buy a pressure washer. A really good one. Take that, moss!
Just after we got the thing I bet David that someone, somewhere had tried pressure washing his/her horse and had posted about it on the intertoobs.