Black Sooty Mold on Plants

The honeydew produced by aphids feeds both black sooty mold and ants.

Black sooty mold is a common occurrence on both indoor and outdoor plants. Once it has been identified, it should be treated immediately.

Causes

The University of Florida states that black sooty mold grows from honeydew, which is a sweet sticky substance excreted by small insects like aphids and mealybugs. While the honeydew is harmless itself, it gives the sooty black mold food to grow on.

Impact

As black sooty mold grows, it covers the surface of the plants' leaves. While the black sooty mold is harmless itself, it shades the plants' leaves and prevents it from taking in light. Over time, the leaf yellows and dies off.

Treatment

Treat sooty black mold by getting rid of the insect problem. Sooty black mold will disappear once you get rid of the insects that are causing the issue. The University of Florida recommends using an insecticidal soap on the affected leaves.

References

• University of Florida: Black, Sooty Mold on Landscape Plants