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Canna Lily · Canna indica

Why are there orange spots on my Canna Lily leaves?

Those orange or brown spots are often a sign of rust, a common fungal issue for Canna Lilies. Check the undersides of your leaves first to see if you can spot the powdery spores.

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spots on a plant
Photo: Scot Nelson, CC0

Check these first

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

Likely causes

  1. 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.

  2. 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.

Leaf spots on other plants

Find out what's wrong with your canna lily

The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant 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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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.

Canna Lily: spots? Check yours with a photo

Every plant is a little different. Take a photo of your canna lily and Pocket Botanist tells you which cause is most likely, how serious it is, and what to try first. A few checks a day are free. Save the plant and you get care reminders timed for it.

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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.

Guides to these causes

More problems with Canna Lily

Back to the Canna Lily guide

This article was generated with AI on from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.