Foam at Tree Base: Bacterial Wetwood (Slime Flux)

A tree has a foam-like substance at the base attracting bees, flies, and ants. Owner asks what it is.

Diagnosis

Bacterial wetwood (slime flux). Anaerobic bacteria ferment heartwood, producing fatty acids and gas pressure that forces sap out through cracks. The ooze is foul-smelling, slimy, and attracts insects.

Key Points

• Not a decay fungus—infected wood resists decay.
• No cure; flux usually stops on its own.
• Do not apply wound dressings.
• Remove loose bark; let area dry.
• Surface disinfect with 10% bleach (1:9) to deter insects.

Tree health is unaffected if crown remains vigorous.