Cottonwood Slime Flux: Insects on Sap, Fertilize Tree

Lightning-struck cottonwood has 3-ft wet streak with bugs in it. Slime flux.

Slime Flux (Wetwood)

• Internal bacterial infection → gas pressure forces sap out wounds.
• Sap fermented, foul, alkaline; kills grass below.
• Insects feed on sugars—secondary.

Management

• Spray insects with carbaryl (Sevin) if nuisance.
• No cure for flux. Drain tubes outdated (spread bacteria).
• Fertilize: 10-10-10 at 1 lb/inch trunk diameter, scattered, watered in (before rain).
• Avoid wounding; prune properly.

Bottom Line

Slime flux is chronic. Kill nuisance insects, fertilize for vigor. Tree can live years with it.