Is this fungus harmful?

It is not fatal immediately, but it prevents the plant from photosynthesizing well.

Can I wash the spots off?

You can wipe them off, but the fungus is still inside the leaf tissue. You need a fungicide or natural treatment to stop it.

Bitter sneezeweed: spots, causes and fixes

Check these first

Examine the leaves for a dusty white coating.
Check if the plant is crowded by other shrubs.
Look for signs of high humidity around the plant base.

Likely causes

Powdery mildew
Most likely
How to tell: White, flour like patches appear on the leaves and stems.
What to do: Prune away the most affected leaves to improve airflow. Apply a neem oil spray or a mixture of water and baking soda to the leaves.
Poor circulation
Possible
How to tell: The plant is crowded by other vegetation, keeping moisture trapped on the leaves.
What to do: Thin out nearby plants to allow more air to move around your sneezeweed. Avoid overhead watering to keep the foliage dry.

Leaf spots on other plants

Find out what's wrong with your bitter sneezeweed

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

Treat this as soon as you see it, as it can spread to the whole plant and weaken it over time.

Stopping it coming back

Give your plants plenty of space to breathe and always water at the base, not over the leaves.

Bitter sneezeweed: spots? Check yours with a photo

Every plant is a little different. Take a photo of your bitter sneezeweed 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

Is this fungus harmful?: It is not fatal immediately, but it prevents the plant from photosynthesizing well.
Can I wash the spots off?: You can wipe them off, but the fungus is still inside the leaf tissue. You need a fungicide or natural treatment to stop it.

Guides to these causes

Powdery Mildew

Why does my Bitter sneezeweed have white spots?