Black Knot on Plum Tree: Prune, Sanitize, Fungicide for Prevention

Black knot galls on plum branches release spores. Prune 4–6 inches below knots, disinfect tools between cuts (1:9 bleach). Destroy pruned wood.

Fungicide (Preventive Only)

Fruit is safe to eat—disease only affects plums/cherries. Prune after harvest. Avoid overhead watering. Scout nearby wild plums/cherries for knots.

Plant Diseases: Black Knot Disease on Flowering Plum: Pruning and Prevention; Plum Tree Leaf Curl and Eggs: Beneficial vs. Pest Identification; Black Knot Disease on Plum: Pruning and Fungicide Protocol; Plum Tree Loose Bark with Magenta Spores: Complex Diagnosis Needed; Black Knot on Ornamental Plum: Organic Atomic Grow Treatment; Flowering Plum Black Knot: Identification and Control; Plum Tree Soft Bark Bumps: Scale Insect Infestation; Black Knot on Plum Trees: Pruning, Spraying, and Saving Your Tree; Black Knot Disease on Plum Tree: Fruit Impact and Control; Black Knot Disease on Stone Fruit Trees: Pruning Out Infected Limbs

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