November 26, 2018

Plant Health Experts: Don’t Compost Those Boxwood Wreaths

Contact:   Donna Gilson (608) 224-5130, donna.gilson@wi.gov
                Bill Cosh, Communications Director, (608) 224-5020, William2.Cosh@wi.gov

MADISON – If you’re decorating with boxwood wreaths or boughs this holiday season, watch where you place them and be sure to dispose of them properly when January rolls around.

“If you decorate with boxwood, keep it away from boxwood or Pachysandra plantings in your yard,” says Brian Kuhn, director of the Plant Industry Bureau in the Wisconsin Department of Agriculture, Trade and Consumer Protection. “At the end of the season, don’t compost the decorations. Place them in sealed plastic bags and put them in your garbage.”

The reason to take these precautions is boxwood blight, a fungal disease found in Wisconsin for the first time this past July. Although it’s been detected in only one nursery in southeastern Wisconsin, boxwood decorations may come from other states that have the disease. State plant health officials are on the lookout and would like holiday decorators to do the same.

Boxwood is popular in landscaping as an evergreen shrub. Unlike most other evergreens, it has tiny leaves rather than needles. Plants infected with boxwood blight, caused by the fungus Calonectria pseudonaviculata, develop brown leaf spots and black lesions on their stems. Eventually the leaves turn yellow or brown and drop off. The fungus may also spread to two species of Pachysandra, commonly known as Japanese spurge and Allegheny spurge. Like boxwood, they are popular in landscaping, used as evergreen groundcovers.

DATCP nursery inspectors will be watching for boxwood blight and other pests and diseases in Christmas trees and other decorations when they conduct tree lot inspections beginning November 26. The inspectors visit Christmas tree fields in autumn to assure that trees destined for other states are free of pests and diseases. When tree lots open in Wisconsin, they also visit those businesses. In recent years, they have found imported trees, wreaths, and holiday decorations infested with elongate hemlock scale, an invasive pest that is not established in Wisconsin. In those cases, the items cannot be sold and plant health officials in the home state are notified.