What's Hot at the PPDL
December 15, 2017
Boxwood Blight on Holiday Greenery
Gail Ruhl, PPDL; Megan Abraham, IDNR
DISEASE ALERT: Boxwood Blight on Holiday Greenery
Wreaths with boxwood blight are on the ‘naughty list’
The Indiana Department of Natural Resources (IDNR), Division of Entomology and Plant Pathology was recently notified by the North Carolina Plant Industry Division of a potential boxwood blight contaminated shipment of mixed evergreen Christmas wreaths. Over five hundred wreaths were received on November 22nd by Boy Scout Troop 399 in Evansville Indiana and sold as part of an annual fundraising event.
A wreath (Fig 1) with leaf spot and stem canker symptoms (Figs 2,3 ) of the fungal disease, boxwood blight, was collected by the IDNR and sent to the Purdue Plant and Pest Diagnostic Lab (PPDL) for testing. The boxwood blight fungal pathogen, Calonectria pseudonaviculata , was confirmed on symptomatic leaves and stems of boxwood sprigs intertwined amidst the mixed conifer greenery.
Click Image to enlarge
Figure 1. A. Rust, IDNR 
Figure 2. BB Leaf Spots, N. Gregory University DE 
Figure 3. BB stem A. Rust, IDNR Boxwood blight disease is highly contagious and destructive to boxwood shrubs, (Fig4) an extremely popular landscape plant. This disease is very difficult to control and eradicate, once established in an area. Other landscape plants in the boxwood family, including Pachysandra and Sarcococca (sweetbox) are also susceptible. There is no danger or risk to humans.
Figure 4. bugwood, M.A. Hansen, VPI The IDNR has issued an alert (Click here for alert) asking all people who bought wreaths from Boy Scout Troop 399 to immediately place the wreath in a plastic trash bag and return it to the tree lot on West Franklin Street before Sunday, December 17 so they can be destroyed.
The DNR is also asking customers to leave their name, address and contact number when wreaths are dropped off, particularly those individuals who did not pre-order their wreaths. This information will allow the IDNR to follow up this coming summer to check boxwoods in the landscape for symptoms.
There have been no confirmed Indiana finds of boxwood blight and we are hopeful that this will be a contained incident and not spread to boxwood in the landscape.
Links to the news coverage this is generating are below.
http://www.14news.com/story/37049384/alert-contaminated-christmas-wreaths-sold-in-evansville
