Tree Bark Dark Growth: Wood Borer Wound with Fungal Infection

Diagnosing Bark Damage

Dark growth on bark with possible sawdust = wood borer entry wound infected with fungus/mold. Beetles bore in; fungi colonize the moist wound.

Why It's Dangerous

• Weakens tree structurally.
• Stress signals attract more borers.
• Fungus can spread internally.

Immediate Disinfection

• Hydrogen peroxide or dilute ammonia on wound.
• Do not seal—trap moisture.

Systemic Support

• 10-10-10 time-release fertilizer to drip line.
• Don't overfertilize.
• Monitor for new holes.