Variety of Methods Needed to Protect N.C. Hemlocks

The hemlock woolly adelgid is responsible for the deaths of thousands of North Carolina hemlock trees over the past two decades, but an integrated approach to pest management is showing positive results for the trees’ long-term survival.

Agriculture Commissioner Steve Troxler was updated on hemlock restoration efforts at a recent meeting at DuPont State Recreational Forest, which straddles Henderson and Transylvania counties and has several stands of hemlocks. The hemlock’s range includes all of Western North Carolina.

“The hemlock woolly adelgid has decimated Carolina and eastern hemlocks by sucking the sap of young twigs and causing tree death,” Troxler said. “No single method is going to restore hemlocks to long-term health, so we’re focused on bringing together all the knowledge and support at our disposal to solve the problem.”

Since 2014, the N.C. Department of Agriculture and Consumer Services has made two allocations totaling $350,000 from the state’s legal settlement with the Tennessee Valley Authority to support the Hemlock Restoration Initiative. The investments are supporting direct interventions on state and private lands, coordination of resources, and increasing volunteer efforts to save hemlock stands throughout the state. Additional funding has been provided by the N.C. Forest Service, U.S. Forest Service, Buncombe County and private donations. WNC Communities, an Asheville nonprofit, is managing grants and providing administrative support for the program.

The Hemlock Restoration Initiative has helped treat thousands of trees on conserved and state-owned lands, assisted with the release of more than 6,000 beetles that eat hemlock woolly adelgids, co-hosted a forum on biological control agents, and informed dozens of landowners about how to treat their own trees.

Margot Wallston, hemlock restoration coordinator with WNC Communities, said landowners can get involved in hemlock restoration in a number of ways:

  • Treat hemlocks on their own property.
  • Volunteer for a hemlock treatment workday on a state forest, park or game land.
  • Use native, locally sourced trees and other plants in landscaping to avoid introducing other unwanted pests.
  • Feed adelgids to predator beetles being raised at the NCDA&CS Beneficial Insect Lab. The lab will come and collect portions of infested hemlock branches. Call 919-233-8214 for more information.
  • Inform the Forest Restoration Alliance about potentially adelgid-resistant “survivor trees” that stand out in a stand of dead hemlocks.

The effort to save hemlocks is like a marathon, Wallston said, and the funding has given the effort “a burst of energy for the long haul.”

Unlike plant diseases such as chestnut blight that can affect a variety of tree species, the hemlock woolly adelgid is a single type of insect affecting hemlocks, Wallston said. “It can be controlled. As long as we can control it, then those trees can survive to maturity.”