Sooty mold refers to a layer of mostly harmless black fungal mold that can accumulate on palm leaves. It can be easily scraped off with one’s finger. There are several species of sooty mold fungi in Hawaii. These fungi are not parasitic on plant and therefore cause no infection to palm leaves. However, sooty mold is a nuisance and can block light from reaching plant leaves. The sooty mold fungi consume the sugary exudates (honeydew) that land on leaves from the feeding activities of sap-feeding insects such as mealybugs and scales. In order to control sooty mold, one must first control the insects responsible for the honeydew accumulation and the ants which tend to them and protect them from their natural enemies.
Back to the Palm