Pocket Botanist
Check these first
- Examine the spots to see if they have a yellow halo.
- Check if the spots are appearing on the lower or upper leaves.
- Look for signs of high humidity or poor airflow around the tree.
Likely causes
Fungal leaf spot
Most likelyHow to tell: Small brown or black spots appear on the leaves, sometimes with a yellow halo. These spots may grow and cause the leaf to drop early.
What to do: Remove and destroy any fallen leaves to stop the fungus from spreading. Improve air circulation by thinning out crowded branches.
Environmental stress
PossibleHow to tell: Spots appear after a period of extreme weather or chemical exposure. The spots are often irregular and not centered around a specific infection point.
What to do: Ensure the tree is getting enough water and avoid spraying chemicals near the foliage. The tree will usually grow out of this once conditions stabilize.
Find out what's wrong with your box elder
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
Worry if the spots cover most of the leaf surface or if the tree loses its leaves prematurely. It is normal to see a few minor spots on older leaves late in the season.
Stopping it coming back
Water at the base of the tree rather than overhead to keep the leaves dry. Keep the area around the tree clean of debris.
Keep your box elder healthy from here
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Questions people ask
- Do I need to use a fungicide?
- Usually not, as these spots are rarely fatal. Good sanitation and proper watering are almost always enough.
- Will the spots go away?
- The existing spots will not disappear, but the new growth should be healthy if you address the underlying cause.
More problems with Box elder
This article was generated with AI from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.