Rust guide image
Plant disease guide

Rust

Symptoms: Orange, yellow, brown, or rusty pustules, often on leaf undersides. Leaves may yellow and drop.

Symptoms: Orange, yellow, brown, or rusty pustules, often on leaf undersides. Leaves may yellow and drop.Prevention note: Water at the base, clean up fallen leaves, and avoid crowding susceptible plants.

Quick facts

Symptoms: Orange, yellow, brown, or rusty pustules, often on leaf undersides. Leaves may yellow and drop.

Organic treatment / management:

Prevention note: Water at the base, clean up fallen leaves, and avoid crowding susceptible plants.

  • Remove infected leaves.
  • Increase airflow.
  • Avoid wetting leaves.
  • Use sulfur or copper sprays only when label-safe for the plant.

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 Rust?

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.