Hemlocks are dying because of an invasive insect pest called the hemlock woolly adelgid (HWA). HWA was introduced to eastern North America from Japan in the early 20th century, and is now rapidly spreading throughout the native range of hemlock. It began to impact trees in North Carolina in the early 2000s. HWA attaches itself to the base of the hemlock needle and feeds on the tree’s stored nutrients and starches. Over time, the tree begins to lose its needles, decreasing its ability to photosynthesize. The tree declines and eventually dies in as little as four years after infestation. For more information, see our page Hemlock Woolly Adelgid.
Returning NC's Hemlocks to Long-Term Health