Causes and Treatment of Bark Splitting on Dogwood Trees

Common Causes

• Frost cracks: Rapid temp swings freeze trunk water → splitting (SW side).
• Sunscald: Winter sun thaws bark, night freeze kills tissue.
• Growth fluctuations: Dry then wet spells cause rapid expansion.
• Thin bark, young trees most susceptible.

Prevention

• White trunk paint or tree wrap (winter).
• Avoid late-season high-nitrogen fertilizer.
• Gradual thinning, not heavy pruning.

Treatment

• Do NOT paint/seal. Wound dressings hinder healing.
• Tracing: Sterile knife, clean split edges ½–1″ back. Remove loose bark. Leave open.
• Boost vigor: Spring fertilizer if deficient, adequate water.

Key Takeaway

Bark splits are usually environmental. Clean edges (tracing) and tree vigor promote natural callusing.