Can I use household bleach for killing moss on roofs?

Asked March 23, 2014, 1:48 PM EDT

Someone told me that I can use a mixture of household bleach and water in my backpack sprayer to kill moss on roofs...of course being careful not to spray any surrounding foliage etc.. Wondering if this is good advice and if so what ratio of bleach to gallon of water would you recommend? Would this also work for killing the moss on my paved driveway?

Lane County Oregon

1 Response

Hello, thanks for your question. I don't know whether/how bleach would kill moss, or whether it might damage the roofing material, paint, gutters, or sidewalk. If your goal is to avoid using pesticides, bleach is also a pesticide, but it hasn't been evaluated for this purpose. With a pesticide registered to kill moss on roofs and driveways, you would have the assurance that the risks had been fully evaluated, and necessary measures to protect you, your property, and the environment would be clearly stated on the label. With bleach, you would be taking unknown risks. While that's your prerogative, I cannot advise you.

There are several products registered in Oregon for moss control on roofs and driveways. If you're looking for something with low toxicity in general, consider looking for the signal word of CAUTION. That indicates low toxicity. If you see "WARNING" or "DANGER", that means moderate or high toxicity. Thanks again for your question!