Plum Tree Dying Back: Likely Brown Rot Blossom Blight

Your Minnesota plum set fruit last year but didn’t produce; this year top/west half died, no leaves. Sounds like brown rot blossom blight (fungal).

Check for Life

Scrape bark on branches: green = alive; brown = dead. Work down until green found. If none, tree is dead.

If Alive: Management

1. Prune all dead wood (back to green).
2. Fertilize, mulch, water deeply.
3. Sanitation: remove mummified fruit, fallen leaves.
4. Avoid overhead watering.
5. Fungicide schedule: apply at pink bud, full bloom, petal fall. Options: chlorothalonil (Daconil), copper, myclobutanil (Immunox), sulfur (not during bloom west of Cascades).
6. Control insects that wound fruit.

If Dead

Remove tree and roots. Replant resistant variety (e.g., ‘Mount Royal’, ‘Stanley’) in well-drained site with full sun.

Bottom Line

Brown rot is common on plums. Sanitation + timed fungicides + vigor = control. If too far gone, replace with resistant cultivar.