Brown or dark leaf spots

Spots can reflect damage, infection or environmental stress.

Cercospora spots on eggplant; leaf spots have many possible causes. Photo: Scot Nelson · CC0 · Resized and converted for display.

What to look for

Note whether spots are spreading, water-soaked, dry or surrounded by yellow. Check both leaf surfaces and nearby plants; a photo alone rarely establishes whether a spot is fungal or bacterial.

What to do

Remove badly damaged leaves when practical using clean tools. Give foliage room to dry, avoid splashing leaves and monitor new growth. Do not apply a treatment until the likely cause is clearer.

Sources

University of Minnesota Extension · Plant disease management
University of Minnesota Extension · Spotting plant problems