Camellia Black Coating: Sooty Mold from Aphids

The black, tar-like substance on your camellia leaves and stems that rubs off is sooty mold growing on honeydew from aphids (likely camellia aphid or tea scale). The ants you see are farming the honeydew.

Control

1. Control aphids/scale:
   • Horticultural oil (thorough coverage, undersides)
   • Systemic (imidacloprid soil drench)
   • Insecticidal soap (for aphids)
2. Sooty mold will wash off with rain once insects are gone—no fungicide needed.
3. Ants will leave when honeydew source is gone.

Camellia Health

• Yellowing leaves may be from: high soil pH (camellias need 5.0–6.0), nutrient deficiency, or root stress.
• Test soil pH; amend with sulfur if >6.5.
• Fertilize with acid-loving plant food (azalea/camellia formula).

Fix the insects first; the black coating will disappear. Then address the yellowing.