Is powdery mildew contagious to other plants?

Yes, the spores travel easily through the air. Keep an eye on your other garden plants if you see it on your Sneezewort.

Should I cut the plant back if it has spots?

If the infection is severe, cutting the plant back by half can help it regrow fresh, healthy foliage. Just make sure to dispose of the infected clippings in the trash, not your compost.

Why does my Sneezewort have white spots? Causes and fixes

Check these first

Rub the white spots with your finger to see if they wipe off like dust.
Check if the plant is crowded by other garden neighbors.
Observe if the spots appear after a period of high humidity.

Likely causes

Powdery Mildew
Most likely
How to tell: You will see a white, dusty coating on the leaves that looks like flour. It usually starts on the older leaves and spreads upward.
What to do: Prune away the most heavily infected leaves to improve airflow. Spray the remaining foliage with a mix of 1 tablespoon of baking soda in a gallon of water.
Poor Air Circulation
Possible
How to tell: The plant is crowded by other plants or growing in a stagnant, humid corner. The spots appear quickly after a rainy spell.
What to do: Thin out nearby plants to give your Sneezewort more room to breathe. Ensure it is planted in a location that gets a good breeze.

Leaf spots on other plants

Find out what's wrong with your sneezewort

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 the fungus covers the entire plant, it will stop photosynthesis and cause the leaves to die. Treat it early to keep the plant looking good.

Stopping it coming back

Water at the base of the plant rather than overhead to keep the leaves dry. Space your plants out during planting to ensure good airflow.

Sneezewort: spots? Check yours with a photo

Every plant is a little different. Take a photo of your sneezewort 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

Is powdery mildew contagious to other plants?: Yes, the spores travel easily through the air. Keep an eye on your other garden plants if you see it on your Sneezewort.
Should I cut the plant back if it has spots?: If the infection is severe, cutting the plant back by half can help it regrow fresh, healthy foliage. Just make sure to dispose of the infected clippings in the trash, not your compost.

Guides to these causes

Powdery Mildew

Why does my Sneezewort have white spots?

Check these first

Not sure what's wrong with your sneezewort?