Boxwood Blight Found at Indiana Garden Center

Matthew Chappell

It’s pretty bad news for folks in Indiana, as Purdue University and Indiana’s Department of Natural Resources, Division of Entomology and Plant Pathology announced in mid-October that container boxwoods at a number of retail outlets have tested positive for boxwood blight. The infected plants have been linked to a shipment of infected boxwood plants that were shipped to Indiana in May.

This is important because boxwood blight (Calonectria pseudonaviculata) is a fungal disease that infests members of the popular Buxaceae family, and is often transported through the nursery trade. Hosts include Buxus (boxwood), Pachysandra (Japanese spurge) and Sarcococca (sweetbox).

In total, 23 stores in Indiana received infected material in early spring (particularly the cultivar Graham Blandy) and it’s possible that landscape contractors inadvertently purchased some plants. If you did, or suspect you have, please contact your respective DNR staff member.

The fungus, which can lay dormant in drier conditions, can be found on all above-ground portions of the plant and presents itself as dark leaf spots. It causes rapid defoliation, which typically starts on the bottom of the plant and moves toward the top. This fungal pathogen can move through sporulation in water and from dropped leaves. As a result, infection can spread to surrounding plants from a single infected plant. GT