Landscape Report


Boxwood Blight – Be on the Look-Out

Boxwoods losing leaves should not be ignored!!  Check them carefully for tell-tale symptoms of boxwood blight, a serious fungal disease that causes rapid defoliation and dieback (Fig. 1). The fungus that causes boxwood blight can infect all above ground portions of the shrub. The first symptoms of the disease are dark leaf spots (Fig. 2 ) that progress to twig blight and rapid defoliation (Fig. 3)  and eventual death of the plant if it goes undetected (Fig 4).   The narrow black streaks (cankers) that develop on green stems (Fig. 5), are a unique symptom that differentiates boxwood blight from other boxwood diseases.  During periods of high humidity, white, fuzzy masses that consist of numerous clumps of spores will emerge from these black stem cankers (Fig. 6) as well as on the underside of leaf spots. The spores can be observed on infected stems and leaves with a hand lens. These spores can be splash-dispersed through irrigation or rainfall, spreading the disease within a plant or to other nearby boxwood shrubs. Pachysandra is also susceptible to this disease and may become infected from rain/wind splashed spores.

Fig 7 Infected boxwood in mixed evergreen wreath (PPDL)

This fungus is easily transported in the nursery industry and can be moved on symptomless infected plants, as well as on shoots of infected boxwood greenery tucked into evergreen Christmas wreaths (Fig. 7).

Since the first U.S. detection in 2011, boxwood blight has been reported in more than 20 states and three Canadian provinces. Boxwood blight has not yet been detected in Indiana landscapes or nurseries but in all reality –it is just a matter of time. It is imperative to be aware of the tell-tale symptoms of boxwood blight and to send suspect samples to the PPDL when you see symptoms of this serious fungal disease in boxwoods in the landscape or nursery.

For more background and in-depth information on this disease please refer to our Purdue publication BP-203-W at

Additional information:

Virginia Boxwood Blight Task Force

Share This Article
It is the policy of the Purdue University that all persons have equal opportunity and access to its educational programs, services, activities, and facilities without regard to race, religion, color, sex, age, national origin or ancestry, marital status, parental status, sexual orientation, disability or status as a veteran. Purdue is an Affirmative Action Institution. This material may be available in alternative formats. 1-888-EXT-INFO Disclaimer: Reference to products in this publication is not intended to be an endorsement to the exclusion of others which may have similar uses. Any person using products listed in this publication assumes full responsibility for their use in accordance with current directions of the manufacturer.

Sign-up to receive email news and alerts from Purdue Landscape Working Group: