Blight: Prevention and Control
If you’re seeing rapid browning, spotting, or plants suddenly declining—especially in warm, wet conditions—blight may be the cause.
Overview
Blight is a fast-moving plant disease
It causes rapid browning, leaf death, and plant decline
It spreads quickly in warm, humid, and wet conditions
Common Signs
Dark brown or black spots on leaves
Spots spread quickly and merge
Leaves may collapse or shrivel
Fruit may show dark, sunken areas
Often Confused With
Leaf spot
→ smaller, slower-moving spots
Wilt
→ plant droops without leaf spotting
Blight spreads quickly and damages large sections of the plant
Plants Commonly Affected
Tomatoes
Potatoes
Peppers
Eggplant
Occurrence
Most common during warm, wet weather
Spreads during rain, humidity, or overhead watering
Often starts on lower leaves and moves upward
Fast Control (Start Here)
Remove infected leaves immediately
Keep foliage dry and improve airflow
Mulch to prevent soil splash
Remove plant if infection is spreading rapidly
Which Treatment Should You Use?
For early signs
→ Remove affected leaves and improve conditions
For ongoing risk
→ Use preventative fungicide if needed
For severe spread
→ Remove plant to protect others
Do not rely on treatment alone
Instructions
Immediate Action
Remove affected leaves while dry
Bag and dispose — do not compost
Clean tools after each plant
Environmental Control
Water at the soil line
Avoid overhead watering
Space plants for airflow
Prevention
Space plants properly
Water at the soil line
Use mulch to prevent soil splash
Use mulch and prune plants to keep leaves off the soil
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 spreading rapidly, remove the entire plant
If You Pull Plants: Compost or Trash?
Do not compost
Bag and trash infected plants
Can You Plant Again in the Same Space?
Not immediately
Rotate crops away from that area
Avoid planting tomatoes, peppers, or potatoes there next season
Gardener’s Notes
Blight is one of the most destructive garden diseases
It can spread quickly during wet weather
Early action matters more than treatment strength
Key Takeaway
Act fast
Remove infected tissue early
Keep foliage dry
Prevent spread, don’t chase it
