I found black sooty-looking mold on the leaves of my Hoya plant. I checked my gardening book and found a picture that looked like what I have. The book said it was residue from red spider mites. Is this correct? If so, what insecticide should I use? I have the plant hanging on my patio. Should I move it inside?
Black Sooty Mold on Leaves of Hoya
Certified GKH Gardening Expert
Yes, I would definitely check for mites. They will be very small and will be on the underside of the leaves. When you see webbing, it is usually from mites. This article will help with treatment:
It is true that sooty mold is normally a result of a pest infestation, be it mites, aphids or scale. Neem oil can be used to treat both the mites (or other pest)as well as the fungus. These articles will help: https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm