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Coral Bark Maple Black Sap Spot and Mottled Leaves: Graft Incompatibility

Coral bark maple trunk

Black sapping spot at base with one-sided leaf mottling/pinking indicates graft incompatibility. The scion (top) and rootstock grow at different rates, disrupting vascular alignment.

Outcome

No cure—nutrient/water movement impaired.
Continue normal care; monitor progression over weeks.
Tree may stabilize or decline.

This is a structural graft issue, not a treatable disease.

Plant Diseases: How to Treat Sunscald on Young Red Maple Trees; Identifying Lichen vs. Disease on Maple Trunks and Managing Frost Cracks; Coral Bark Maple Decline: Balancing Water in Pacific Northwest; Coral Bark Japanese Maple Decline After Repotting: Root Stress; Coral Bark Japanese Maple Trunk Discoloration: Cold Injury; Maple Trunk Bark Peeling: Wound Care (Bark Scoring); Japanese Maple Bark Loss: Oak Root Rot or Insects?; Coral Bark Maple Winter Kill: Scrape Test for Life; Coral Bark Maple Fall Growth Spurt: Stress Response; Coral Bark Maple Identification

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