Blight guide image
Plant disease guide

Blight

Symptoms: Rapid dark water-soaked areas on leaves, stems, or fruit. Plants may collapse quickly.

Symptoms: Rapid dark water-soaked areas on leaves, stems, or fruit. Plants may collapse quickly.Prevention note: Avoid wet conditions, space plants well, use mulch to prevent soil splash, and choose resistant varieties.

Quick facts

Symptoms: Rapid dark water-soaked areas on leaves, stems, or fruit. Plants may collapse quickly.

Organic treatment / management:

Prevention note: Avoid wet conditions, space plants well, use mulch to prevent soil splash, and choose resistant varieties.

  • Remove infected plant parts immediately.
  • Do not compost badly infected material.
  • Use copper products preventively where appropriate.
  • Rotate crops outdoors.

What to do next

  • Remove the worst infected or damaged tissue when appropriate.
  • Improve airflow, spacing, sanitation, and watering habits.
  • Avoid overhead watering when leaf disease is suspected.
  • Use organic fungicide or copper products only when the label fits the plant and disease.
  • Discard confirmed viral infections rather than propagating from them.

Watch-outs

Do not compost severe disease material unless your compost system gets hot enough to destroy pathogens.

FAQ

How do I use this plant disease guide?

Start with the light, soil, water, symptom, or purpose notes on this page, then make one careful change at a time.

What is the biggest mistake with Blight?

Do not compost severe disease material unless your compost system gets hot enough to destroy pathogens.

When should I get more help?

Get local help if the plant is valuable, symptoms are spreading quickly, or outdoor disease and pest problems may affect nearby plants.