Sooty Mold on Ginkgo: Wipe Test and Insect Control

Sooty Mold on Ginkgo: Wipe Test and Insect Control

Black coating on ginkgo leaves that rubs off with a wet finger is sooty mold—fungi growing on honeydew from sap-feeding insects (aphids, scale, whitefly). The mold is cosmetic; the insects are the problem.

Steps

1. Confirm with the wet-finger test.
2. Inspect leaf undersides and stems for insects.
3. Treat with insecticidal soap, neem oil, or systemic imidacloprid based on pest found.
4. Sooty mold will weather off once honeydew stops.

Google "sooty mold images" to compare. Healthy ginkgos tolerate light infestations.