Conservation Outdoors

Conservation: Hemlock Restoration Inititative

Dead and dying hemlocks in the Green River Game Lands near Saluda. Photo by Margot Wallston

By Emma Castleberry

The scourge of the hemlock woolly adelgid (HWA), an invasive pest, continues to endanger the survival of swaths of hemlock trees in Western North Carolina and beyond. “It’s crucial that we deal with hemlock woolly adelgid because this invasive insect is the single greatest threat to hemlock trees in our region,” says Thom Green, outreach manager for the Hemlock Restoration Initiative (HRI). “Without intervention, we will likely lose all or nearly all of our hemlocks, both in forested and residential areas.”

Hemlocks are a foundation species and their loss negatively impacts forests as a whole through reduced water quality, higher stream temperatures, increased severity of flooding events, loss of plant and wildlife habitat—including trout habitat in streams—and reduced biodiversity. These impacts have all been reported in forests with high hemlock mortality rates in areas where the HWA has spread, including North Carolina and the Southern Appalachian mountains. “Hemlocks have a high value in residential and urban areas too,” adds Green. “They help slow and reduce stormwater runoff, decrease heating and cooling costs, filter air pollution, make great privacy screens, provide urban wildlife habitat and reduce the urban heat island effect.”

Wooly adelgid on a hemlock branch. Photo by Margot Wallston

The HRI has been working tirelessly to protect these trees, but the method of treatment for hemlocks infected with the HWA has historically been expensive and time-consuming, requiring application by a professional—until now. New, affordable methods of treatment that can be completed independently by landowners are now available. “Chemical treatment is the most reliable way for a landowner to protect their hemlocks against HWA, and for trees that pose a risk to safety or structures, chemical treatment is much cheaper than tree removal,” says Green. The HRI is partnering with the Flat Rock Playhouse to host a demonstration of chemical treatment methods on Saturday, November 6, from 9:30 a.m. to 12:30 p.m. at the Flat Rock Playhouse Gardens. There will be a second demonstration on Friday, November 12, at the Cashiers Historical Society from 9 a.m. to 4 p.m.

The demonstrations will provide an opportunity for participants to practice assessing hemlock health to determine the best treatment options, learn how to use the new chemical treatment methods and understand when other methods or approaches (such as hiring a tree care professional) might be best. “We will discuss environmental considerations in detail and the steps landowners can take to apply the products in ways that minimize exposure to the environment,” says Green. “Even if they only plan to have a professional do the treatment, the information we are going to present will help them make informed decisions when hiring someone.”

Local landowner Matt Baker learned to love hemlocks at a young age while hiking through the Smoky Mountains. “The adelgid has been devastating and incredibly sad to see,” he says. “Not only are hemlocks a critical species, but they are also key landscaping trees that add value to properties and provide great shade.” When Baker moved onto his property in 2017, it already had many established, healthy trees that had been previously treated for the HWA. “After a few years, I started to notice signs of new infestations along with severe infestations on my neighbor’s trees,” Baker says. “I came across HRI and contacted them for advice. They helped walk me through the simple process to treat my own trees and now I’ve even helped my neighbors treat theirs.” Baker calls the process “super simple” and says he would recommend it to anyone with hemlocks on their property.

Hemlock management training along the Valley River near Murphy. Photo by Sara Ruth Posey

Even for landowners without any existing hemlocks on their property, the demonstrations of this new method can provide valuable information. “Some landowners may have had hemlocks in the past but have lost them all to HWA, and those landowners may be interested to hear how they can protect hemlocks that they might like to replant,” says Green. “Also, people often overlook the small hemlocks that may be hiding in the understory of the wooded portion of their property. These can be easy to keep healthy with some of the methods we will demonstrate.”

Visit for more details about each demonstration and to register. There is a suggested donation of $20 per household. Each household will also receive some materials to help get them started treating their own hemlocks. Email or call 828.252.4783 with questions about the event.

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