Crepe Myrtle Sooty Mold: Sucking Insect Control with Systemic Insecticide

Problem Analysis

Two crepe myrtles with black trunk/branch areas, poor performance last summer. Neighbors' trees unaffected. Eastern exposure.

Diagnosis: Sooty Mold from Sucking Insects

• Black fungus = sooty mold
• Grows on honeydew (sugar-rich insect excrement)
• Produced by: aphids, scales, whiteflies, mealybugs
• Insects suck plant juices → secrete honeydew → mold grows on sugar

Solution: Systemic Insecticide

Bayer Advanced Tree & Shrub Insect Control (soil drench):

• Applied to soil under tree
• Roots absorb → translocate to branches/leaves
• Sucking insects killed when feeding
• Timing: Before leaf-out (dormant/early spring)
• Sooty mold weathers off once honeydew stops
• Available at local nursery/garden centers

Why This Approach

Foliar sprays miss insects on leaf undersides and in crevices. Systemic delivers insecticide directly to feeding site through plant's vascular system. Season-long protection with single application.