Black Spot (Internal Black Spot)
Alternaria spp.
1 host plant · Fungal
Last updated
Data Coverage 3 of 6 dimensions
Black Spot (Internal Black Spot) can show up on landscape plants, producing visible damage that ranges from leaf spots and discoloration to branch dieback depending on severity. Early detection gives you the best management options.
Start with sanitation: remove and dispose of affected material as you find it. Thin dense growth to improve air circulation, and redirect irrigation away from foliage. If the condition persists despite cultural adjustments, your local Extension office can help identify the pathogen and recommend targeted treatments.
Quick Reference
Agent Type
fungal
Causal Agent
Alternaria spp.
Host Plants
1
Management
Cultural Controls
- Plant cultivars known to be resistant in your area.
- Note that the cultivar Carefree Spirit was the first landscape shrub to survive for 2 years in AARS tests without any fungicide and voted a winner.
- Avoid dense plantings and shaded areas.
- Avoid overhead watering that keeps plants wet for extended period of time.
- Rake up and burn all leaves in a rose planting at season's end.
- Prune canes back to two buds if canes are infected.