Key Features
- Blight throughout the canopy
- Dieback
- Black stems without defoliation
Symptoms
Boxwood decline results in random twig dieback, with the foliage remaining attached to the affected branches. Bright black staining occurs under the bark and is present in infected stems.
Biology
Boxwood dieback commonly begins through the leaves, with the pathogen spread from plants due to poor pruning practices, and by the dispersal of conidia via rain or irrigation water. This disease is often introduced by new planting stock.
Management Recommendations
Evaluate new plants prior to introducing them into the landscape. Remove infected plants. Preventative applications of fungicides is needed to prevent infection; fungicides will not 'cure' already infected plants.
Effective Pesticides
Active Ingredients include: Chlorothalonil, Thiophanate-methyl
Resources
- Not satisfied with ID? Contact the Purdue Plant and Pest Diagnostic Lab
- Sign Up for the Purdue Landscape Report
