How to Manage Pests

Pests in Gardens and Landscapes

Bacterial leafspot of cole crops—Pseudomonas syringae pv. maculicola

Infections of bacterial leafspot start as small, dark specks on leaves. As the disease develops, numerous water-soaked leafspots appear. Leafspots remain small (0.125 inch in diameter). Older leafspots turn tan and may or may not have a purple border around them. Leafspots are visible from both the top and bottom sides of leaves.


Bacterial leafspot occurs primarily in cooler regions such as in coastal areas. The pathogen that causes the disease is seedborne and is splashed from plant to plant by rain and sprinkler irrigation. Plant clean seed and disease-free transplants. Avoid sprinkler irrigation. Remove and discard of any diseased plants.

Bacterial leafspot on cabbage
Bacterial leafspot on cauliflower

Statewide IPM Program, Agriculture and Natural Resources, University of California
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