Bark Splitting and Sap Flow in Fruit Trees and Maples: Sunscald Management

Jane has lost multiple fruit trees and maples to bark splitting with sap oozing ("bleeding"). One peach tree in its third summer shows the same issue. She suspects spread from a tree removed last year.

Primary Cause: Sunscald (Frost Cracks)

Rapid winter freeze-thaw cycles cause bark to split, often on south/southwest sides. Splits may not appear until warm weather triggers sap flow. Thin-barked trees (peach, maple) are most susceptible.

Treatment for Existing Splits

1. Trace and clean: With a sharp knife, cut ½ inch beyond split edges through bark only. Remove loose bark.
2. Disinfect: Swab with 10% bleach solution. Let dry—no wound paint needed.
3. Assess severity: Splits encircling trunk = tree likely dead. Multiple splits on one limb = consider removing that limb.

Prevention Strategies

• No late fertilization: Stop nitrogen by mid-summer to harden growth before winter.
• White trunk paint: Apply diluted white latex paint to lower 4 ft of young trees in fall (preventive only—not on existing wounds).
• Borer vigilance: Peach tree borers (clear-wing moths) attack stressed trees. Monitor for frass and treat if needed.
• Canker watch: Splits invite canker fungi. Prune out limbs with expanding dead areas.

Long-Term Care

Consult your county extension for region-specific peach care calendars. Proper pruning, thinning, and pest management reduce stress that predisposes trees to sunscald.