Sycamore Black Bark Under Peeling: Fungal Vascular Disease and Extension Testing

Diagnosing Black Bark Layer

Peeling outer bark revealing black inner bark on 30–40 ft sycamores in dry Texas = fungal vascular infection (likely Ceratocystis canker stain or similar). Black streaks in vascular tissue; fungi can spread via root grafts.

Why It's Serious

• One tree already dead.
• Second showing same symptoms.
• Thin canopy + drought stress = rapid decline.

Critical Step: Lab Diagnosis

County extension lab can culture bark samples to ID exact fungus. This guides:

• Species-specific management.
• Risk to nearby trees.
• Potential trunk injection treatments.

Immediate Actions

• Water deeply to reduce drought stress.
• Avoid wounding.
• Monitor all sycamores weekly.