Rust

Rust is a group of fungal diseases that can affect certain bonsai species.

Signs of Rust

Look for yellow or orange spots, orange, brown, or rust-coloured pustules, premature leaf drop, or reduced vigour.

The characteristic coloured spores are often found on the underside of leaves.

What to Do

Remove affected leaves where practical and dispose of fallen foliage.

Improve airflow and avoid keeping foliage unnecessarily wet.

Persistent infections may require an appropriate fungicide.