Treating Recurring Brown Spots on Mature Boxwoods

Likely Blight or Canker

Fourteen-year-old and younger boxwoods develop brown spots that kill sections, ruining their shape. Several fungal diseases (boxwood blight, Volutella canker, Macrophoma leaf spot) cause similar symptoms.

Get a Precise Diagnosis

Take a sample (affected leaves and stems in a sealed bag) to your local cooperative extension or a reputable nursery. They can identify the specific pathogen and recommend the correct fungicide.

Cultural Practices to Reduce Disease

• Prune only in dry weather; sanitize tools between cuts.
• Thin dense growth to improve air circulation.
• Avoid overhead irrigation; water at the base.
• Remove and destroy fallen leaves.
• Apply a preventive fungicide in spring if disease history is severe.

Accurate ID + targeted treatment + good culture = healthy boxwoods.