Q: In Highlands, NC the hemlock population has been destroyed. I have four beautiful twelve-year-old hemlocks. Is there anything proactive that I can do to prevent the insects from creeping into my trees?
A: The most proactive thing you can do is to examine the needles each month for the insect that kills hemlock trees: the wooly adelgid. The creatures are easy to spot, especially in spring. They look like white pieces of fluff among the young needles. There is no need to apply anything until you see the pest on your trees. But keep an eye on other hemlocks in your neighborhood. If you spot adelgids on nearby trees, use a soil drench containing imidacloprid or contact an arborist.