Snapdragon: Rust

categories: Flowers Ornamentals Snapdragon Snapdragon Diseases

revision date: 2023-02-07 12:00

Severe snapdragon rust.
Severe snapdragon rust
Photo by: R.S. Byther


Rust is caused by a fungus that is spread by water or on clothes and in diseased cuttings. It is not carried in seed but seeds can be contaminated by the fungus on the outside. Upper leaf surfaces have diffuse pale or yellow spots. Under the leaf are concentric rings of chocolate-brown pustules. Pustules are on stems and flowers also. The infected plant may appear stunted and dry.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

  • Space plants to encourage good air circulation.
  • Do not water foliage or water only in morning or in the middle of the day when the foliage will dry quickly.
  • Rust-resistant snapdragon cultivars are available.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

  • Focus on cultural management options for best results.