Pocket Botanist
Check these first
- Rub the white spots to see if they wipe off like dust.
- Check for air circulation around the center of the shrub.
- Look for yellow halos around dark spots.
Likely causes
Powdery mildew
Most likelyHow to tell: You will see white, dusty patches on the leaf surfaces that look like flour. It often starts on the older leaves and spreads to the new growth.
What to do: Improve air circulation by thinning out crowded branches. Apply a fungicide labeled for powdery mildew or a mixture of water and baking soda every 7 to 14 days.
Cercospora leaf spot
PossibleHow to tell: Small, dark, angular spots appear on the leaves, often with a yellow halo. These spots may eventually turn gray or brown as the tissue dies.
What to do: Remove and destroy all fallen leaves around the base of the plant to stop the spread of spores. Avoid overhead watering to keep the foliage as dry as possible.
Find out what's wrong with your viburnum
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
Powdery mildew is mostly cosmetic but can cause leaf drop if left untreated for a long time. It is rarely fatal to a mature viburnum.
Stopping it coming back
Water at the base of the plant rather than over the leaves, and prune the shrub to allow better airflow through the canopy.
Viburnum: spots? Check yours with a photo
Every plant is a little different. Take a photo of your viburnum 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
- Should I cut off all the spotted leaves?
- You can remove heavily affected leaves to improve the look of the plant. Just make sure to dispose of them in the trash rather than the compost bin.
- Is this fungus going to kill my plant?
- No, powdery mildew is usually just a seasonal nuisance. Your plant will likely bounce back just fine next year.
Guides to these causes
More problems with Viburnum
- Why are there holes in my viburnum leaves?
- Why are my viburnum leaves turning yellow?
- Why are my viburnum's leaf tips turning brown?
- Why is my viburnum drooping?
- Why is my viburnum losing its leaves?
- Why is my viburnum not blooming?
- Is my viburnum suffering from root rot?
- Why is my viburnum looking so leggy?
- Why are my viburnum leaves curling?
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.