published Saturday, May 18th, 2013

Lea: Check hemlocks for wooly adelgids

By Pat Lea

Q. What is the latest news on the Hemlock wooly adelgid infestation? I hear this blight is getting worse.

A. I am impressed that you know the full name of the threat to our native hemlocks. HWA is a serious pest that has caused thousands of hemlocks to die in the last few years.

Right now, hemlock lovers should check their hemlocks for white masses at the base of the needles. You will see bright white, fluffy masses that look like a dusting of snow. Inspect closer, and you will see they are thicker on the underside of the needles. When squashed with your finger, a reddish brown or orange goo oozes out. These are the crawlers, and they are hatching now. They have emerged from eggs laid last fall and are ready to start sucking the life out of our hemlocks.

The insect produces mature adults twice every year. They can destroy a large hemlock in less than three years. Some trees will succumb faster, and some can survive longer but, as far as researchers have seen, all will die if the tree is not treated. Treated trees may need extra applications because re-infestation can occur, but the new chemicals can protect the trees for more than a year.

Two chemicals knock out the pest: one is long-lasting, the other is quickly effective. Consult the Master Gardeners website -- -- or or our state extension service at for information. Our extension agent can be reached at 423-855-6113.

The procedures are somewhat complex, and the treatment is very specific. Concerned gardeners should consult these sources if they want real answers to the problem of Hemlock wooly adelgids.

There is definitely hope for our hemlocks, and they are a beautiful and crucial part of our ecosystem. They deserve your study and attention.

Email lea.pat@gmail com.

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