Fungal disease
Aloe Rust
A fungal disease that marks aloe leaves with round yellow spots that turn brown or black, sometimes with rusty, raised pustules.
Symptoms
- Round yellow spots that darken to brown or black
- Raised, rust-coloured or orange pustules on the leaf
- Damage mostly on the surface; the leaf usually stays firm underneath
What causes it
Rust spores spread on air and water and take hold in cool, damp, humid conditions.
What you can do
- Keep the plant away from other aloes until it improves.
- Remove badly affected leaves with clean scissors and bin them rather than composting.
- Keep leaves dry and the air moving around the plant.
- Clean up any fallen leaves from the pot surface.
Not sure it's rust?
Photograph one affected leaf and Plantulus will suggest the most likely problem, with a confidence score. It's free and needs no sign-up.
Check a leaf photoOther aloe problems
General guidance only, not a diagnosis. Check product labels and local rules before using any treatment, and ask a horticultural specialist if a valuable plant is struggling. See the disclaimer.