Leaf Spots and Blights
Phyllosticta sp. and Dothiorella candollei (formerly Macrophoma candollei)
2 host plants · Fungal
Last updated
This profile contains verified disease data from extension databases. Regional field notes and expert review are in progress.
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
- Cut out all dead branches. Remove dead leaves from crotch areas inside the canopy. Space and prune (thin) plants for good air circulation. Thinning is best done in the fall during dry weather using sharp bypass pruners. Grow plants in well-drained media or soil with a pH between 6.8 and 7.5. Light shade of 20% can also reduce injury from summer and winter extremes.