Leaf spot guide image
Plant disease guide

Leaf spot

Symptoms: Brown, black, tan, or yellow-ringed spots on leaves. Severe infections can cause early leaf drop.

Symptoms: Brown, black, tan, or yellow-ringed spots on leaves. Severe infections can cause early leaf drop.Prevention note: Reduce leaf wetness, sanitize pruners, and keep infected leaves out of compost if disease is severe.

Quick facts

Symptoms: Brown, black, tan, or yellow-ringed spots on leaves. Severe infections can cause early leaf drop.

Organic treatment / management:

Prevention note: Reduce leaf wetness, sanitize pruners, and keep infected leaves out of compost if disease is severe.

  • Remove infected leaves.
  • Water at soil level.
  • Use compost tea only as a supportive soil practice, not a cure-all.
  • Use copper or sulfur products only when appropriate and label-safe.

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 Leaf spot?

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.