My house must be a magnet for algae. I have green algae on the shaded parts of my deck; it’s also on my patio and my vinyl siding. Furthermore, I believe there’s black mildew on my siding. Then there’s the roof. I have black streaks of algae up there. How can I safely remove the algae from all these surfaces without harming me, my pets or my plants? I’ve heard that bleach works, but something tells me that this is not the right approach.— Caroline B., Jackson, Miss.
You, I and millions of others suffer from algae around our homes. I have two decks, one on top of another. The lower deck has lots of shade, which is a perfect place for algae to grow. I also have algae coating stone steps on my property. I work at keeping them clean, because when they’re wet, the algae-covered steps are as slippery as wet ice.