Managing sooty mold on fruit trees

NORTH COUNTY – Sooty mold is an unsightly, dark fungus that grows on fruit, leaving it looking spotted and dry. Sooty mold doesn’t make the fruit inedible (if washed off before eating), but it can be harmful to the plants themselves if it is allowed to grow out of control. It can completely cover leaves, preventing photosynthesis and causing early leaf-fall.

The fungus thrives on honeydew, a sticky substance left behind by certain plant-sucking insects. The insects take their fill from the plant, but can’t always use it all; what they can’t use is excreted as honeydew. Many of these inse...