Boxwood blight has been detected in a South Carolina plant nursery, marking the second appearance of the fungal disease in the state, according to officials with the Department of Plant Industry (DPI) at Clemson University.
The first identification of Cylindrocladium buxicola, also called Cylindrocladium pseudonaviculatum and Calonectria pseudonaviculata, in South Carolina was in March, when landscapers near Florence found it.
According to DPI assistant department head Steven Long, the fungus appeared to have been present there for several years. It was suspected in the earlier case that the plants came from an out-of-state nursery.
Since the disease is not a “pest of concern” in South Carolina, it is not regulated outside of commercial nurseries.
Now that has all changed with the discovery of the infection in an Upstate nursery. Inspectors are currently conducting “traceback and traceforward” investigations to determine the movement of the stock bought and sold at the nursery.
“The infected nursery is working with us to destroy all affected plants and clean up the affected nursery environs,” Long said. “The nursery also has agreed to follow a strategic document created by DPI that lays out a plan of eradication and clean-up.”
DPI will be monitoring the nursery’s adherence to the process and working with the business to put other protective measures in place.
Boxwood blight appeared in the United States in 2011 and quickly spread from North Carolina to Virginia and other states. Some states such as Pennsylvania have enacted quarantines to prevent the spread. The disease is suspected of spreading to new states primarily through infected stock.
“The most likely means of contracting boxwood blight is primarily through the purchase of infected nursery stock material,” Long said. “Once in a given area, it can be spread by homeowners’ and landscapers’ failing to properly sanitize pruning equipment as they move through their yard or community.”
Boxwood blight manifests itself in rapid defoliation, black cankers, leaf spots and severe dieback. It usually doesn’t kill the plant, but it does weaken the shrub to the point that other diseases are likely to kill it.
“Boxwood blight can spread blight to all foliage and stems on susceptible boxwood cultivars,” Long said. “It is extremely detrimental to many boxwoods and almost always requires plant removal and extensive environmental cleanup.”
For those who see symptoms of boxwood blight, it is important to have a specialist identify the disease accurately.