Sap Bubbling on Plum Tree: Canker, Woodpeckers, or Wound Response

What does sap bubbling from a plum tree mean?

Three Main Causes

1. Bacterial Canker (Pseudomonas)

• Sunken, oozing cankers on trunk/branches
• No cure—manage stress, prune dead wood

2. Woodpecker Damage

• Rows of small holes in horizontal lines
• Sap feeds birds/insects
• Usually minor, cosmetic

3. Physical Wound

• Mower/string trimmer hit, frost crack, pruning cut
• Tree compartments naturally
• No paint/sealant needed

Assessment

Look for hole patterns (woodpeckers) or canker margins (bacterial). Most plum trees tolerate moderate sap flow.