How to Remove Sooty Mold from Citrus Trees
Sooty mold indicates that your citrus trees have an insect infestation. It is usually found on the bottom of a tree's leaves. The insects that cause sooty mold--mealybugs, whiteflies and aphids--are typically more active during cooler weather. Mold forms from a honeydew secretion that the insects leave after feeding on the tree. You can remove sooty mold with store-bought insecticides or homemade solutions.
Spray both sides of infected tree leaves with Big Buster insecticide. Use a second treatment 10 to 14 days after your first application if your trees have a severe infestation.
Spray your trees with liquid Gold Copper when mold develops. Apply it only to infected leaves. Stop a large outbreak by respraying infected leaves 10 to 14 days after the first treatment.
Mix 1 cup of cooking oil with 1/2 cup of water. Place a small amount of dish soap in the mixture, then spray it on the infected leaves. This homemade spray will smother the insects.
Remove Sooty Mold On Bushes
Sooty mold, a black mold that covers shrub leaves and other plants, looks more alarming than it is. Despite its dirty appearance, sooty mold doesn't generally hurt shrubs, but the sap-sucking insects that cause the mold can compromise the plant. Mix 1 teaspoon of dish soap with 1 gallon of lukewarm water. Wipe the soapy water over the areas and leaves affected by the mold, gently rubbing until the mold loosens. Rinse the leaves with clean water as you go. Look for insects including aphids, whiteflies, leafhoppers, mealybugs and scale. Spray infected parts of the plant with pre-mixed insecticidal soap spray, coating the insects directly until the leaf area is dripping slightly.