will spraying moldy cocoa mulch harm my plants?

Question

We just went through an extremely hot and humid weekend and when I went out to look at my flower border, there was a fine mold on top of the cocoa bean mulch. An article on your site says to spray with 25% water 75% white vinegar, but will this harm my plants? This is my first year of using this type of mulch…

Answer 1

This can harm the plants, and I would advise this between crops, or before planting. White, or gray mold is normal, and harmless, and sometimes beneficial. Other colors such as dark green, black, or dark gray can indicate a problem.

I would, instead, suggest spraying with pure peroxide. Avoid the plants when this is not diluted, but spraying the mulch will be just fine.