Why Boxwood Decline Is Increasing in Pennsylvania Landscapes

---

Boxwood decline has become one of the most common concerns we see in Pennsylvania landscapes. Unlike boxwood blight, decline is not a single disease—it’s a complex stress response caused by multiple interacting factors.

Boxwood decline often results from a combination of:

• Root stress from compacted or poorly drained soils
   
• Winter injury and salt exposure
   
• Repeated drought stress
   
• Insect pressure (boxwood leafminer, mites, psyllids)
   
• Opportunistic fungal pathogens
   

Once stressed, boxwoods lose vigor, foliage thins, and branches begin to die back—often starting on one side of the plant.

• Bronzed or yellow foliage
   
• Leaf drop inside the canopy
   
• Branch dieback
   
• Poor spring flush
   
• Sparse or stunted growth
   

While there is no single “cure,” decline can often be stabilized or reversed with the right approach:

• Improve drainage and soil structure
   
• Avoid excessive pruning
   
• Maintain consistent irrigation
   
• Use targeted insect control only when needed
   
• Apply soil health amendments and root-supportive treatments
   

In severe cases, replacement with disease-resistant boxwood varieties or alternative shrubs may be the most sustainable option.