Rhododendron: Rust

Biology

Yellowish spots on the upper leaf surface and dark brown or purple spot on the lower leaf surface can indicate the presence of a rust infection. Later, the underside develops blisters which break open to reveal characteristic yellow to orange or reddish spores. Rusts can also affect azaleas. The disease overwinters on the host plant.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

• Prune and destroy infected leaves.
• Clean up and destroy any diseased leaves that have fallen to the ground.

Chemical Management

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

• None recommended