Is powdery mildew harmful to the whole plant?

It can be if left unchecked, as it blocks the plant from photosynthesizing properly. Treating it early keeps the plant strong.

Can I use a store bought fungicide?

Yes, you can use a garden safe fungicide if the baking soda mix does not work. Always follow the instructions on the label.

Dandelion: spots, causes and fixes

Check these first

Look closely to see if the white spots rub off like dust.
Check if the plant is crowded by other foliage.
Observe if the plant is in a very humid or still spot.

Likely causes

Powdery Mildew
Most likely
How to tell: You will see a white, flour like coating on the surface of the leaves. It often starts as small patches and can spread to cover the entire leaf.
What to do: Mix one tablespoon of baking soda with a gallon of water and spray the leaves lightly. Remove the most heavily infected leaves to stop the fungus from spreading.
Poor Airflow
Possible
How to tell: The plant is crowded by other vegetation or sitting in a stagnant, humid corner. This lack of breeze encourages fungal growth.
What to do: Thin out nearby plants to create space for air to move around your dandelion. If the plant is in a container, move it to a more open area.

Leaf spots on other plants

Find out what's wrong with your dandelion

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

A few small spots are manageable, but if the fungus covers most of the leaves, it will weaken the plant significantly. Treat it early to avoid stunted growth.

Stopping it coming back

Keep the leaves dry when watering and ensure the plant has plenty of space for air to circulate.

Dandelion: spots? Check yours with a photo

Every plant is a little different. Take a photo of your dandelion 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 powdery mildew harmful to the whole plant?: It can be if left unchecked, as it blocks the plant from photosynthesizing properly. Treating it early keeps the plant strong.
Can I use a store bought fungicide?: Yes, you can use a garden safe fungicide if the baking soda mix does not work. Always follow the instructions on the label.

Guides to these causes

Powdery Mildew

Why are there white spots on my dandelion leaves?