| White powdery substance on the back of the leaves and the leaves are turning yellow |
| What you describe sounds like sooty mold. Sooty mold is a charcoal black fungus that appears as a black coating on the surface of leaves, fruits, twigs and branches of many deciduous and evergreen shrubs and trees. It is a sign of insect feeding. When sucking insects such as aphids, whiteflies, mealybugs and scales feed, they exude a sticky substance called honeydew. This substance has a high sugar content which then attracts mold spores. The sooty mold will weather away once you control the insect infestation. You can use insecticidal soap sprays to discourage the insect population (repeated sprays may be required). Once you have them under control, there will be no more sooty mold. |
