How do I clean mold and lichens on wooden Adirondack furniture?
I have a bunch of almost 30-year old unpainted wooden Adirondack furniture on my deck that has been exposed to harsh weather over the years. I've noticed lately that green mold and lichens are growing on the wood, especially on the north side of the deck that gets very little sun. How do I clean this furniture and how can I insure that it won't grow back? I prefer not to paint or stain it.