Ag Department Warns of Boxwood Blight During Spring Cleanups
Wednesday, March 02, 2016
Posted by: Dana Rhodes, Pa Dept. of Agriculture
HARRISBURG - Boxwood Blight is a fungal disease which affects the Buxus genus and several other plant genera. Leaf spotting and sudden defoliation of the plants begins toward the base and moves upwards. The plants may leaf out again, but ultimately will die.
There are no curative fungicides available for the disease, only preventatives which will mask any symptoms until the fungicide applications end. The leaf spotting and stem lesions seen with boxwood blight may look like other diseases of boxwood. Only lab analysis can diagnose boxwood blight.
Once boxwood are infested, they cannot cured. Infected material must be destroyed. The best methods are burning or burying at least three feet deep. All leaf debris must be included in the destruction. Spores for boxwood blight are viable for more than 10 years. Always check with your local township or regional DEP office to make sure you are in compliance with ordinances.
Because the spores last for so long, boxwood plants with the disease should never go into compost. Currently Penn State University is working on what temperatures and for how long plants would need to be held to kill the spores. When this information is available, it will be shared.
Currently, the Pennsylvania Department of Agriculture (PDA) is working with DEP on guidelines for use of landfills for boxwood blight material. The guidelines will include how to safely bag material, transport, and dump at landfills. Guidelines for haulers and township recycling yards is also in the works. These guidelines will be finalized prior to May. If there are large quantities of boxwood which may need to be landfilled, you will need to contact PDA and work with your regional plant inspector.
If you suspect you may have boxwood blight, please contact your local Penn State Extension Office. They will assist in sampling and diagnosis. PDA is working with Extension Educators throughout the state to educate green industry, home owners, and master gardeners on symptoms, testing and proper disposal.
If you are not sure if the boxwood dieback you may be seeing from the winter is boxwood blight or winter dieback, please contact your local extension office for additional information or sampling.
If you are a producer or large seller of boxwood you might consider the Boxwood Clean Program offered by PDA. This program is a voluntary program. The producer or handlers agree to minimize the possible introduction of Boxwood Blight through best management practices. The participants are recognized by the state for safe production and handling. Participants names are listed on the PDA website for customers to see. If you are interested in this program please contact your local PDA Regional Plant Inspector.