Controlling Sooty Mold on Tulip Trees by Managing Aphids

Cause of Sooty Mold

The black, soot‑like coating is a fungus growing on honeydew excreted by aphids feeding on leaves and twigs.

Control Strategy

Kill the aphids, and the mold will weather away. For large trees, a systemic insecticide injected into the trunk (by a professional) or a high‑pressure foliar spray is needed. Contact the St. Louis City Forester (Jim Vaughan, 952‑924‑2565) for local applicator recommendations.