If you’re seeing small dark spots on leaves or fruit—sometimes with a yellow halo—and the plant starts to lose lower leaves, bacterial spot or speck may be the cause.
Overview
Bacterial spot and speck are common bacterial diseases
They cause small dark lesions on leaves, stems, and fruit
They spread quickly in wet conditions and can reduce plant health
Common Signs
Small dark brown or black spots on leaves
Spots may have yellow halos
Leaves may yellow and drop early
Fruit may develop:
Tiny black specks (speck)
Larger rough, scabby spots (spot)
Often Confused With
Leaf spot
→ usually more uniform, slower spreading
Blight
→ rapidly expanding dead areas
Distinguishing feature:
Bacterial spot/speck often look wet, greasy, or sharply defined, and can affect fruit more noticeably
Plants Commonly Affected
Tomatoes
Peppers
Eggplant
Related nightshades
Occurrence
More common in warm or wet conditions
Spread by rain, irrigation, and splashing water
Often begins on lower leaves and moves upward
Fast Control (Start Here)
Remove infected leaves early
Avoid overhead watering
Keep foliage dry
Limit plant-to-plant contact
Which Treatment Should You Use?
For early signs
→ Remove affected leaves and adjust watering
For ongoing risk
→ Use preventative copper sprays if needed
For widespread infection
→ Focus on sanitation and limiting spread
Do not rely on sprays alone
Instructions
Immediate Action
Remove spotted leaves while dry
Dispose of infected material
Clean tools after handling plants
Environmental Control
Water at the soil line
Avoid overhead watering
Improve airflow between plants
Prevention
Use disease-free seeds or transplants
Space plants properly
Avoid working with wet plants
Remove plant debris at end of season
Sanitize tools and supports
When to Remove Plants
Mild infection
Remove affected leaves
Monitor closely
Severe infection
If leaves and fruit are heavily affected, remove the plant
If You Pull Plants: Compost or Trash?
Do not compost infected plants
Bag and dispose of them
Can You Plant Again in the Same Space?
Yes, with precautions
Remove all debris
Rotate crops if disease was severe
Gardener’s Notes
Bacterial diseases spread quickly in wet conditions
Watering habits are a major factor
Prevention is far more effective than treatment
Key Takeaway
Keep leaves dry
Remove infected tissue early
Avoid spreading bacteria with water and tools
Focus on prevention and sanitation
