Cottonwood Bark Split with Insects: Wound Care and Borer Prevention

A large cottonwood has a chest-high bark split with separating bark, visible insects (ants, bees), and exposed smooth wood. Owner wants to prevent death.

Immediate Action

• Remove all loose bark cleanly back to attached bark
• Spray wound with Merit (imidacloprid) to prevent borer colonization
• NO wound dressing—slows healing

Long-Term Process

The tree will gradually compartmentalize and close the wound over years. Decay fungi may enter but typically only affect dead wood. Monitor for:

• Expanding wound
• Fungal conks on trunk
• Progressive crown dieback

Structural Note

Cottonwoods are weak-wooded and prone to failure. If this tree targets structures, consult an ISA-certified arborist for risk assessment regardless of wound healing.