Boxwood Blight

What it looks like

Round, dark-edged leaf spots that merge into brown blotches, followed by fast, heavy leaf drop. Look closely at the stems for narrow black streak-like cankers—that's the key sign of true boxwood blight rather than a milder look-alike disease. Bare, twiggy branches often remain after leaves fall.

Often mistaken for: Volutella leaf blight (bronzing leaves and bark peeling, but no black stem streaking)

When it shows up in the Triangle

It can show up any time of year since it survives on plants and in fallen leaves, but spreads fastest during wet spring and summer weather.

Where you’ll see it

Mainly affects boxwood shrubs, especially American boxwood, and can also spread to pachysandra and sweetbox.

What you can do

• Sanitize pruning tools between every cut with bleach or alcohol
• Never prune boxwood when the foliage is wet
• Remove and bag or burn infected branches and fallen leaves—don't compost them
• Prune to open up the plant for better airflow
• Switch from overhead sprinklers to drip irrigation near boxwoods
• Use bark or compost mulch instead of fabric, and consider resistant varieties if replanting