Honeydew from Linden Trees: Systemic Insecticide for Aphid/Scale Control

Two 20-year-old littleleaf lindens dropping honeydew for years. One overhangs parking—messes cars. Bayer soil drench applied (slow). "Eight" hose-end sprayer reached 3/4 of tree. Leaves on driveway tree have holes. Family wants trees removed.

Cause: Aphids or Scale Insects

Both suck sap and excrete honeydew → sooty mold (black, sticky).

Control Options

• Contact sprays (acephate, bifenthrin, malathion, pyrethrum, etc.)—difficult on large trees; resistance possible
• Systemic soil drench (imidacloprid/Merit/Bayer Advanced)—absorbed by roots, moves to leaves; long-lasting (months); less harm to beneficials

Recommendation

Since spray coverage incomplete, use Bayer soil systemic. Takes ~1 week to act, lasts months. Also controls white grubs in soil. Product link. Check local nursery.