I've noticed that the side of my white house is getting green. Is this mold? How do I fix this? We've alonly lived her 4 years and this is the first year that we noticed it. I also have a white picket fence around my backyard. Part of the fence has started to turn green too.

Any help would be appreciated... OR... please direct me to where I could get some information to stop and prevent this in the future.

Thanks... cb