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Boxwood Blight: How to Protect Boxwoods this Holiday Season

Be careful when introducing boxwood holiday greenery/plants to your home and landscape

Our beloved boxwoods are being threatened. Please help by doing a few key things this holiday season to keep this destructive and difficult-to-control disease at bay. Please be aware of the

potential for the boxwood blight pathogen to be introduced to landscapes on infected boxwood greenery/plants used for wreaths, holiday roping or decoration.

The Essential Info:

Boxwood blight, caused by a fungus, is a serious disease of boxwood that can cause complete defoliation of plants and is difficult to control.

The disease was first found in Virginia in 2011 in Carroll County and has now spread to Chesterfield County, the City of Richmond, and Fairfax County.

No matter where you live in Virginia, WE ALL (nursery growers, landscapers, historic site property managers and homeowners) NEED TO TAKE PRECAUTIONS to minimize the spread of this highly destructive disease to our beloved boxwoods.

Most boxwood cultivars are susceptible to the disease (particularly English and American boxwoods), but some cultivars appear to have a tolerance to this disease. What this means is that although you may not see obvious symptoms of the disease on the plant, it can still be carrying and producing spores that can spread rapidly to nearby susceptible plants.

The bottom line is to be very careful about introducing any boxwood in to your landscape – as greenery for holiday trimmings or as new plants.

Preventative Measures:

Boxwood blight is difficult to control once established, so, the most important means of control is to avoid introduction of infected plant material in the first place.

Homeowners and property managers should make sure to purchase boxwood greenery (and/or new boxwood plants) from reputable suppliers where box blight has not been found. Ask the retailer if the greenery/plants come from a supplier in the Boxwood Blight Cleanliness Program. Growers who have entered this program follow strict best management practices along with routine inspections by the Virginia Department of Agriculture.

All incoming boxwood greenery/plants should be inspected carefully for the characteristic combination of symptoms of the disease - leaf spots, leaf browning, black streaks on stems, and leaf drop. (Refer to the images of box blight symptoms below.)

Wreaths should be assembled away from any existing boxwoods in the landscape.

Any new boxwood plants should be kept isolated from existing boxwoods for a period of at least a month and monitored for disease development.

If you have recently purchased and planted boxwood plants this past Fall, especially in counties where the disease has been found, monitor plants carefully for disease development.

After the holidays, boxwood greenery should not be composted or discarded on-site. It should be bagged (preferably double-bagged) and removed to the landfill.

Note that although the fungal spores do not spread easily by air currents, they can potentially be carried on leaf debris adhering to people’s shoes, on clothing or on tools used to trim greenery.

For businesses: Workers who directly handle greenery or boxwood plants should be educated about the disease.

If you suspect your boxwood has boxwood blight:

Contact your local Virginia Cooperative Extension county office - http://www.ext.vt.edu/offices/index.html and they can assist you in submitting a sample to the Virginia Tech Plant Disease Clinic – and offer additional control recommendations.

The importance of preventing introduction of this disease to landscapes with healthy boxwood plantings cannot be overemphasized. Please help our beautiful, historic boxwoods to continue to live a good, long healthy life.

Leaf spots (left) and black streaking (right) on stems are characteristic symptoms of Boxwood Blight.

Additional information about box blight can be found at the following web sites:

http://pubs.ext.vt.edu/PPWS/PPWS-4/PPWS-4.html

http://www.ct.gov/caes/lib/caes/documents/publications/fact_sheets/plant_pathology_and_ec ology/boxwood_blight-_a_new_disease_for_connecticut_and_the_u.s.__12-08-11.pdf

http://plantpath.cals.ncsu.edu/ornamentals

Virginia Cooperative Extension programs and employment are open to all, regardless of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, genetic information, marital, family, or veteran status, or any other basis protected by law. An equal opportunity/affirmative action employer. Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; Jewel E. Hairston, Administrator, 1890 Extension Program, Virginia State, Petersburg.

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