Aphids and Lichens on Trees: Dual Management Approach

Aphids and Lichens on Trees: Dual Management Approach

Sap dripping from leaves is aphid honeydew; green powder on trunks is lichens. Two separate issues requiring different solutions.

Aphid Control

• Systemic imidacloprid (Bayer Tree & Shrub) soil drench kills aphids as they feed; stops honeydew.
• Apply in spring for season-long protection.

Lichen Management

• Lichens are harmless epiphytes; they indicate clean air and thin canopy.
• Fertilize with 10-10-10 at 1 lb per inch trunk diameter to promote dense canopy that shades them out.
• Do not use baking soda or chemicals—they can damage bark.

Healthy trees naturally suppress both aphids (via predators) and lichens (via shade).