Black Spot
[NOTE: Diplocarpon rosae causes black spot on roses (Rosa spp.); Septoria and...
14 host plants · Fungal
Last updated
Circular black spots with yellow halos develop on leaves. This fungal disease favors wet foliage. Improve air circulation and remove fallen leaves.
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.
Quick Reference
Agent Type
fungal
Causal Agent
[NOTE: Diplocarpon rosae causes black spot on roses (Rosa spp.); Septoria and...
Host Plants
14
Spread
Rain splash from infected fallen leaves to new foliage; overhead irrigation e...
Management
Vulnerability Window
Apply frequently in wet spring weather and occasionally in summer.
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.
Regional Notes
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Host Plants (14)
Adenium obesum Desert Rose, Desert Azalea, Mock Azalea Daphne cneorum Garland Daphne, Rock Daphne, Rose Daphne Hibiscus syriacus Rose, of Sharon Shrub, Althea Kerria japonica Japanese Kerria Japanese Rose Rosa acicularis Wild Prickly Rose Rosa gymnocarpa Little Wood Rose, Wood Rose, Baldhip Rose Rosa multiflora Multiflora Rose Rosa nutkana Nootka Rose Rosa pisocarpa Clustered Rose, Swap Rose Rosa rubiginosa Sweetbriar Rose, Eglantine Rose Rosa rugosa Rugosa Rose, Beach Tomato, Sea Tomato Rosa woodsii Woods' Rose Spiraea densiflora Rose, Meadowsweet, Mountain Spirea, Subalpine Spirea Spiraea douglasii Rose, Spirea
Sources & References
Data Maturity Structured Multiple sources. Expert review underway.