UOG Horizons: Knowledge For Life - What is that black film on your plant?

UOG Horizons: Knowledge For Life - What is that black film on your plant?

UOG Horizons: Knowledge For Life - What is that black film on your plant?


6/23/2026
Sooty mold coats the surface of a citrus leaf
Sooty mold coats the surface of a citrus leaf, creating a black film that develops on honeydew left behind by sap-sucking insects. Photo courtesy of UOG Land Grant
Joseph Tuquero
 
Alfred Daniel Johnson
 

Have you ever noticed a black film covering one of your plants? Technically, it is known as sooty mold - a term used for well over 200 species of fungi. It is a remarkable, but poorly understood, group of fungi. Here in Guam, you might find it growing on a wide range of plants, including fruits and vegetables, ornamentals and forest plants, at any given time of the year.

Read the full story at The Guam Daily Post