Weeping Cherry Gummosis: Identifying and Managing Sap-Like Ooze

What Is Gummosis?

The jelly-like substance on your 10-year-old weeping cherry trunks is gummosis—a symptom, not a disease itself. It's often triggered by Phytophthora fungus entering through wounds (mower damage, sun scald, wind injury) or environmental stress.

Immediate Treatment Steps

1. Prune affected branches back to healthy wood. Bag and discard or bury 12+ inches deep.
2. Excavate cankers: Use a sharp knife to cut out all discolored, oozing bark until only green/white healthy tissue remains.
3. Create buffer zone: Remove a small margin of healthy bark around the wound.
4. Apply copper fungicide immediately after cutting.
5. Sanitize tools with hot, soapy water between cuts.

Preventive Measures

• Keep mulch 6+ inches away from trunk base.
• Protect trunk from mechanical injury (tree guards, careful mowing).
• Ensure good drainage; avoid water pooling at base.
• Apply balanced fertilizer in spring to maintain vigor.

Long-Term Outlook

Weeping cherries are tough when given space, shelter from harsh wind, and proper care. Prompt action on gummosis can save the tree.