Pocket BotanistCheck these first
- Look for spots on the lower leaves first.
- Check if the leaves stay wet long after watering.
- Examine the ground for fallen, infected leaves.
Likely causes
Fungal leaf spot
Most likelyHow to tell: You will notice distinct brown or black spots on the leaves, sometimes with a yellow halo. The spots may grow together and cause the leaf to drop prematurely.
What to do: Rake up and dispose of all fallen leaves to prevent the fungus from overwintering in the soil. Improve air circulation by thinning out crowded branches during the dormant season.
Overhead watering
PossibleHow to tell: Spots appear mostly on the lower leaves where water splashes back from the soil. The foliage stays wet for too long after sunset.
What to do: Switch to watering at the base of the tree using a soaker hose or drip irrigation. Always water in the early morning so the leaves have time to dry out completely.
When to worry
It is mostly a cosmetic issue, but if the tree loses more than half its leaves, it may struggle to store energy for next year. Treat it if you notice the problem spreading rapidly.
Stopping it coming back
Keep the area under the tree clear of debris and avoid wetting the leaves when you water.
Not sure which one it is? Photograph your catalpa.
This page lists the usual causes. Pocket Botanist looks at your actual leaf and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.
Questions people ask
- Will the spots kill my tree?
- No, leaf spot is generally harmless to the overall health of a mature tree. It just looks a bit messy.
- Can I spray the leaves with fungicide?
- You can, but it is rarely necessary. Good cleanup and proper watering habits are much more effective.
More problems with Catalpa
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.