Pocket Botanist
Check these first
- Look for white dust on the leaves.
- Check for squiggly lines inside the leaf tissue.
- Increase space between plants to improve airflow.
Likely causes
Powdery mildew
Most likelyHow to tell: You see white, dusty patches on the leaves that look like flour.
What to do: Improve air circulation around the plant. You can treat it by wiping leaves with a mix of water and a drop of mild dish soap.
Leaf miners
PossibleHow to tell: Winding, pale trails or squiggly lines appear on the surface of the leaves.
What to do: Pick off and destroy the affected leaves to stop the larvae. Keep the plant healthy so it can grow new, clean foliage.
Find out what's wrong with your chrysanthemum
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.
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When to worry
A few spots are manageable, but if they cover most of the leaves, the plant will struggle to photosynthesize. Take action as soon as you see them spreading.
Stopping it coming back
Avoid getting water on the leaves when you water the soil, and keep the plant in a spot with good airflow.
Chrysanthemum: spots? Check yours with a photo
Every plant is a little different. Take a photo of your chrysanthemum 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.
Scan with your phone's camera to get the app
Or go to pocketbotanist.app/get on your phone
Get the app · Or check it from a photo now, free
Questions people ask
- Is powdery mildew harmful?
- It weakens the plant over time by blocking light. It is best to treat it early before it spreads to all the leaves.
- Can I use a fungicide for the spots?
- You can, but improving airflow and keeping leaves dry is usually enough to stop powdery mildew on indoor chrysanthemums.
Guides to these causes
More problems with Chrysanthemum
- Why are my florist's chrysanthemum leaves turning yellow?
- Why is my florist's chrysanthemum drooping?
- Why is my florist chrysanthemum not blooming?
- What are these bugs on my florist chrysanthemum?
- Why is my florist chrysanthemum growing so tall and thin?
- Why are my chrysanthemum's leaf tips turning brown?
- Why is my chrysanthemum dropping its leaves?
- How do I fix root rot in my chrysanthemum?
- Why are my chrysanthemum leaves curling?
Back to the Chrysanthemum guide
This article was generated with AI on from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.