Problem-specific reference photo
under review
Problem-specific reference photo under reviewunder review
Fungal & Oomycete · Plant health field guide
Black spot-like disease
Several fungi can produce dark leaf spots; host identity and the pattern of spread matter before treatment.
Act soonPossible cause—not a diagnosis. Compare the visible signs, plant identity, and growing conditions before treating.
Signs you may notice
- dark circular spots
- fringed margins
- yellowing around spots
- leaf drop
Safe first checks
- Photograph both leaf surfaces, note whether spots enlarge after wet conditions, and confirm the plant species.
- Separate the plant if the problem may spread.
- Remove only badly affected material with clean tools.
- Improve airflow and keep affected foliage dry while you compare the signs.
Can look similar to
Overlapping symptoms are common. Compare these alternatives before choosing a treatment.
- bacterial leaf spot
- anthracnose
- spray damage
What to avoid
Do not assume every spot is infectious or use a disease-specific product without confirming the host and pattern.
Record and follow up
Photograph the same area in consistent light and note whether lesions enlarge, appear on new leaves, or stop after conditions improve.
Seek qualified local help when damage is severe, rapidly spreading, or may involve a regulated pest or disease.
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