Should I cut off all the spotted leaves?

Yes, removing heavily infected leaves helps prevent the fungus from spreading to healthy parts of the plant.

Can I use a fungicide?

You can, but improving airflow and keeping the leaves dry is usually more effective for hedge mustard.

Hedge mustard: spots, causes and fixes

Check these first

Inspect the undersides of the leaves for fuzzy growth or tiny insects.
Check if the plant is crowded by other plants.
Feel the soil to ensure it is not staying soggy for too long.

Likely causes

Downy mildew
Most likely
How to tell: You will see yellow, angular patches on the upper leaf surfaces that eventually turn brown. Often, a grayish, fuzzy mold appears on the underside of the leaves.
What to do: Remove the affected leaves immediately to stop the spread. Improve air circulation around the plant and avoid getting water on the foliage when you irrigate.
Aphid damage
Possible
How to tell: This is less common for this plant, but aphids can cause small, chlorotic spots where they feed on the sap. Look for tiny insects clustering on the new growth or stems.
What to do: Spray the plant with a gentle stream of water to knock the aphids off. If they persist, apply insecticidal soap directly to the insects every 5 to 7 days.

Leaf spots on other plants

Find out what's wrong with your hedge mustard

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

Worry if the spots are spreading rapidly across the whole plant. It is normal for a few older leaves to show minor wear as the season progresses.

Stopping it coming back

Space your plants out to ensure good airflow and always water at the base of the plant to keep leaves dry.

Hedge mustard: spots? Check yours with a photo

Every plant is a little different. Take a photo of your hedge mustard 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

Should I cut off all the spotted leaves?: Yes, removing heavily infected leaves helps prevent the fungus from spreading to healthy parts of the plant.
Can I use a fungicide?: You can, but improving airflow and keeping the leaves dry is usually more effective for hedge mustard.

Why does my hedge mustard have spots on its leaves?

Check these first

Likely causes

Downy mildew

Aphid damage

Find out what's wrong with your hedge mustard

When to worry

Stopping it coming back

Hedge mustard: spots? Check yours with a photo

Questions people ask

Guides to these causes

More problems with Hedge mustard