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Check these first
- Examine the trunk for sunken or discolored bark.
- Check if the spots are oozing sap.
- Look for recent damage from lawn equipment.
Likely causes
Fungal canker
Most likelyHow to tell: You will see localized dead areas on the bark that may look sunken or discolored. Sometimes the bark cracks or oozes sap near the infection site.
What to do: Prune out the affected branches well below the visible damage. Sterilize your pruning shears with alcohol between each cut to prevent spreading the fungus.
Mechanical injury
PossibleHow to tell: Damage from lawn mowers or string trimmers can create wounds that look like spots or sores. These wounds often invite secondary fungal infections.
What to do: Keep mulch away from the trunk to prevent mower damage. If the wound is fresh, keep the area clean and allow the tree to heal naturally.
Find out what's wrong with your japanese zelkova
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
Cankers that girdle the main trunk are serious and can kill the tree. Small branch infections are usually manageable with proper pruning.
Stopping it coming back
Keep the tree healthy with proper watering and avoid wounding the bark. Ensure good air circulation around the canopy.
Japanese zelkova: spots? Check yours with a photo
Every plant is a little different. Take a photo of your japanese zelkova 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
- Can I spray the spots with fungicide?
- Fungicides are generally ineffective against established cankers. Pruning is the most reliable way to remove the infection.
- Should I paint the wound after pruning?
- No, it is better to let the tree seal the wound naturally. Painting can trap moisture and encourage further decay.
More problems with Japanese zelkova
- Why are there sticky spots on my Japanese zelkova leaves?
- Why are my Japanese zelkova leaves curling?
- Why are my Japanese zelkova leaf tips turning brown?
- Why are my Japanese zelkova leaves turning yellow?
- Why is my Japanese zelkova drooping?
- Why is my Japanese zelkova losing its leaves?
- How do I fix root rot on my Japanese zelkova?
Back to the Japanese zelkova 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.