Can I save a leaf with spots?

If the spot is small, you can snip it off. If the whole leaf is covered, it is better to remove the entire leaf to protect the rest of the plant.

Will these spots kill my Canna?

Usually no, but they weaken the plant and make it look messy. Treating it early keeps your Canna blooming strong all season.

Why are there orange spots on my Canna Lily leaves?

Check these first

Inspect the undersides of the leaves for orange dust.
Check if the leaves are staying wet for too long.
Look for signs of overcrowding around the plant.

Likely causes

Rust Fungus
Most likely
How to tell: You will see small orange or brown pustules on the leaf surface. They often appear when humidity is high and air circulation is poor.
What to do: Remove and destroy any heavily infected leaves immediately. Apply a copper based fungicide spray every 7 to 10 days until the infection clears. Avoid overhead watering to keep the foliage dry.
Leaf Spot Disease
Possible
How to tell: These spots are usually darker brown or black with a yellow halo. They spread quickly during rainy weather.
What to do: Prune away affected foliage to stop the spread. Ensure your plants have enough space between them for air to flow freely. Keep the area around the base of the plant free of dead debris.

When to worry

If the spots cover more than half the leaf or spread to the entire plant, it is time to take aggressive action. Small, isolated spots are manageable with regular pruning.

Stopping it coming back

Water at the soil level rather than over the leaves to keep foliage dry. Provide plenty of space between plants to encourage good airflow.

Not sure which one it is? Photograph your canna lily.

This page lists the usual causes. Pocket Botanist looks at your actual leaf and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.

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Questions people ask

Can I save a leaf with spots?: If the spot is small, you can snip it off. If the whole leaf is covered, it is better to remove the entire leaf to protect the rest of the plant.
Will these spots kill my Canna?: Usually no, but they weaken the plant and make it look messy. Treating it early keeps your Canna blooming strong all season.