Can I use a fungicide for the spots?

You can, but it is usually better to remove the damaged fronds and fix the environment. Fungicides are a last resort for this plant.

Do these spots go away?

No, the damaged tissue will not heal. Once you fix the cause, the new growth will emerge healthy and green.

American royal fern: spots, causes and fixes

Check these first

Check if the spots are located on the side facing the window.
Look for yellow halos around the spots.
Ensure the plant has enough space for air to move around it.

Likely causes

Sun scorch
Most likely
How to tell: Brown or bleached spots appear on the fronds that are exposed to direct afternoon sun.
What to do: Move the fern to a spot with partial or full shade. Ensure it is protected from harsh afternoon light, which is too intense for this species.
Fungal leaf spot
Possible
How to tell: Small dark or reddish spots with yellow halos appear on the fronds, often spreading in humid conditions.
What to do: Remove the affected fronds to stop the spread. Improve air circulation around the plant and avoid getting water directly on the foliage when you water.

Leaf spots on other plants

Find out what's wrong with your american royal fern

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.

When to worry

If spots are spreading rapidly across the entire plant, it needs immediate attention. Small, isolated spots from minor sun exposure are usually not a threat to the plant's life.

Stopping it coming back

Keep the foliage dry when watering and provide plenty of shade to prevent heat stress.

American royal fern: spots? Check yours with a photo

Every plant is a little different. Take a photo of your american royal fern 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.

Get the app · Or check it from a photo now, free

Questions people ask

Can I use a fungicide for the spots?: You can, but it is usually better to remove the damaged fronds and fix the environment. Fungicides are a last resort for this plant.
Do these spots go away?: No, the damaged tissue will not heal. Once you fix the cause, the new growth will emerge healthy and green.

Guides to these causes

Leaf Spot

Why are there spots on my American royal fern?