Saving a Liquidambar Damaged by Weed-and-Feed Herbicide

Root Cause

The “weed and feed” lawn product contains a broadleaf herbicide that trees absorb through roots, causing leaf scorch, yellowing, and dieback. The trunk scar suggests secondary borer attack on the stressed tree.

Rescue Steps

1. Stop herbicide use: Switch to fertilizer-only applications; spot-spray weeds with liquid herbicide away from the tree’s root zone.
2. Flush the soil: Water daily with 1 inch of water for 2–3 weeks to dilute residual herbicide.
3. Treat borers: Spray the scar with Merit (imidacloprid) to control borers under the bark.
4. Fertilize: Apply 10-10-10 at 1 lb per inch trunk diameter to support recovery.

Recovery is uncertain but possible if the root system survives.