Leaf Spots and Blights
Phyllosticta sp. and Dothiorella candollei (formerly Macrophoma candollei)
2 host plants
Last updated
Madrone leaves develop small dark spots from Phyllosticta and Dothiorella fungi, occasionally coalescing into larger blotches. Remove affected plant parts, increase spacing for air movement, avoid overhead wetting, and apply fungicides if needed. This is generally a minor issue on landscape trees.
Remove blighted tissue promptly, cutting well below visible symptoms. Improve air circulation by thinning dense growth. Avoid overhead watering, especially during bloom and new growth periods when tissues are most susceptible. For recurring problems, preventive fungicide applications timed to protect new growth can reduce infection, but cultural controls should be your first approach.
Quick Reference
Management
Cultural Controls
- Remove and destroy affected plant parts if an organism is the cause of the problem.
- Protect unaffected plant tissue with appropriate fungicide applications if the problem is caused by a fungus.
- Application timing is critical.
- Read and follow label instructions.
- Avoid wetting leaves if the leaf spot or blight is caused by a fungus or bacteria.
- Increase plant spacing to improve air circulation and speed drying of foliage.