In winter, you can’t help but smile as you watch those first fluffy snowdrops tumble from the sky. The world seems to stop as you’re filled with awe. That’s why we love bringing that magic inside as we decorate with white, fuzzy fake snow along our mantles. All the beauty without any of the mess!

But if you see something similar outside on your hemlocks, those cottony puffs mean trouble. That white fuzz on your tree or shrub branches is a pest, not a white fungus. Hemlock woolly adelgid (HWA) to be exact.

Learn more facts about the hemlock woolly adelgid, including its life cycle and the damage it can do. Plus, as always, we’re here to help you get rid of that pesky tree pest!

Hemlock Woolly Adelgid Facts, Damage, Life Cycle & Treatment

Are you sure that white fuzz on tree or shrub branches is hemlock woolly adelgid?

As its name implies, this specific fuzz only lives on hemlock trees, including eastern hemlocks, Carolina hemlocks, mountain hemlocks and western hemlocks. So, if you don’t have a hemlock, your tree doesn’t have this specific pest. Also, this insect is much more prevalent on the East Coast than the West Coast.

But there are a couple of other pests that may look like the hemlock wooly adelgid. The cottony maple scale, for instance, but this insect most commonly attacks maples. Aphids can also look white and fuzzy. If aphids are your problem, also look for a black sooty mold. HWA will also only be found on the base of the needle where it meets the branch. 

What’s The Life Cycle Of Hemlock Woolly Adelgid?

This tricky pest itself is black but hides under a white waxy cover. It typically lays eggs from late winter through early summer, and those eggs hatch shortly thereafter. The pests keep growing, and when it’s cooler, they’ll eat your tree or shrub’s sap and overwinter on your plant. Come late winter, they’ll begin laying eggs again–unless you stop ‘em. HWA does not move after eggs hatch. The new insects settle where they want to feed, so movement only takes place during two short periods each year.

What Damage Does Hemlock Woolly Adelgid Do To Trees & Shrubs?

In the beginning, your plant will struggle a bit. You’ll see discolored evergreen needles that may drop early  coupled with a lack of growth if left untreated, the pest will continue to do more and more damage to your tree or shrub. Ultimately, your plant could die without your help.

How Can I Control Hemlock Woolly Adelgid? I Want This White Fuzz On My Tree Branches Gone!

Start by applying horticultural oil in late winter or early spring When it’s warmer than 40° but cooler than 70°. This oil kills overwintering insects on your plant. Horticultural oil may also help to control other pests such as Elongate Hemlock Scale and Spider Mites. Have your arborist follow up and use a systemic insecticide later in the season to help protect your tree.

How Long Should I Wait Between Treating Hemlock Trees?

Your arborist may recommend applying dormant oil once each season in spring and late fall. For treatments, your arborist will generally recommend reapplication annually or even less often depending on the product. .

Ready to wipe out this pest and save your plant? Click here for a free consultation!

Hemlock woolly adelgid
Cottony maple scale

Related Blog Posts

Snow Mold
Lawn Care & Maintenance

What Is This Whitish Gray (Or Whitish Pink) Fuzz On My Grass?

What is snow mold? It's a fungal disease that can create patches of whitish gray or whitish pink grass blades in late winter and early spring. Let's talk about how to prevent snow mold and how to get rid of snow mold in your home lawn.
Read More
AS 285177860 Tubakia Maple
Leaf & Needle Problems

What Are These Water Marks On My Tree Leaves?

Tubakia leaf spot on oak is often confused with oak anthracnose. One way to tell them apart is the timing of leaf spots. Learn more.
Read More

Sign Up For Free Tree & Landscaping Tips! 

Subscribe to the "The Sapling," the Davey Blog's email newsletter, for the latest tips to keep your outdoor space in tip-top shape throughout the year.

Plus, receive a free instant download of our landscape seasonal checklists when you sign up!

Image 22@2X
Image 22@2X

Request A Free Consultation

Let's Find What
You're Looking For!