Report Invasive Hemlock Insects This Winter

Posted on by akabelowsky
Small, white hemlock woolly adelgid eggs found on the needles of a tree in Bastian, Virginia, in 2017.

Small, white hemlock woolly adelgid eggs are found on the needles of a tree in Bastian, Virginia, in 2017. / Photo Credit: Bill McNee, Wisconsin DNR

By Mike Hillstrom, Forest Invasive Pest Coordinator, Fitchburg
Michael.Hilstrom@wisconsin.gov or 608-513-7690

Hemlock woolly adelgid (HWA) looms as a major threat to Wisconsin’s hemlock trees. As the infestation of these invasive, aphid-like insects spreads in Michigan and other states in the eastern United States, Wisconsin is preparing to respond when it arrives.

HWA is most evident in winter and spring as fluffy, white, woolly balls that are present at the base of hemlock needles. These fluffy, waxy balls cover adult female adelgids and eggs.

Continue reading “Report Invasive Hemlock Insects This Winter” →

Beware Of Invasive Plants In Your Holiday Décor

Posted on by akabelowsky
The berries of round leaf bittersweet grow in clusters at each leaf axil and are beautiful, but this highly invasive plant makes it unsuitable for use in your fall decorations.

The berries of round leaf bittersweet (Celastrus orbiculatus) grow in clusters at each leaf axil and are beautiful, but this highly invasive plant makes it unsuitable for use in your fall decorations. / Photo Credit: Chris Evans, University of Illinois, Bugwood.org

By Wisconsin DNR

With the holiday season drawing near, it’s time for the Wisconsin Department of Natural Resources (DNR) to remind home crafters to be wary of using invasive plants in fall and winter decorations.

While holiday decorations made from natural materials can be beautiful, some wreaths and other home decorations may contain invasive species.

A quick Google or Pinterest search for décor ideas brings up a slew of orange-tinged images: pumpkins, leaves, pinecones and pretty fall foliage — sometimes boasting small, red-orange berries. While you can safely cloak your home in most of these items, avoid the one with the red-orange berries, as it likely comes from the non-native, woody vine called round leaf bittersweet (Celastrus orbiculatus, previously known as Oriental bittersweet).

Continue reading “Beware Of Invasive Plants In Your Holiday Décor” →

Take Advantage Of Mild Winter Days To Prune Trees

Posted on by akabelowsky
An arborist uses climbing safety gear to prune an oak tree along a road.

An arborist uses climbing safety gear to prune an oak tree along a road. / Photo Credit: Wisconsin DNR

By Mike Hillstrom, Forest Invasive Pest Coordinator, Fitchburg
Michael.Hilstrom@wisconsin.gov or 608-513-7690

Winter is an ideal time to perform trimming, cutting and brush removal work on and near trees, especially oak trees.

Winter is the best time to prune because the insects and diseases that attack oak trees, such as oak wilt, are not active. Pruning and other work can be done around oak trees from after the first hard freeze in the fall until the high-risk period for oak wilt begins in April.

Continue reading “Take Advantage Of Mild Winter Days To Prune Trees” →

Stumping Heterobasidion Root Disease With Cellu-Treat®

Posted on by akabelowsky
Photo of a freshly cut tree stump after treatment with fungicide to prevent infection with Heterobasidion root disease. The fungicide is dyed blue to help ensure complete coverage.

A freshly cut tree stump after treatment with fungicide to prevent infection with Heterobasidion root disease. The fungicide is dyed blue to help ensure complete coverage. / Photo Credit: Wisconsin DNR

By Tim Shively, DNR Forest Health Specialist, Eau Claire
Timothy.Shively@wisconsin.gov or 608-772-6974

Treating freshly cut conifer stumps is critical to preventing infection by Heterobasidion species, causal agents of Heterobasidion root disease (HRD).

Within this genus, H. irregulare is believed to be the only species in Wisconsin, and it causes the mortality of overstory pine and spruce trees. The DNR has developed comprehensive guidelines to assist landowners, property managers, foresters, and loggers with determining whether stump treatments are necessary to prevent the introduction or spread of HRD at a given site.

Continue reading “Stumping Heterobasidion Root Disease With Cellu-Treat®” →

Did You Know? Facts About Pine Webworm

Posted on by akabelowsky

By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov or 920-360-0665

Webbing and a collection of frass (caterpillar excrement) around these cones is the web nest of pine webworm. / Photo Credit: Wisconsin DNR

Pine webworm (Pococera robustella) is a native moth whose caterpillars feed on pine needles. In Wisconsin, the caterpillars prefer young jack pine and red pine. A single generation per year occurs in Wisconsin.

Young larvae mine needles, feeding within the needle. Older larvae form a compact web that they fill with small, oval pieces of frass. In early fall, the larvae drop to the ground to pupate and spend the winter.

Continue reading “Did You Know? Facts About Pine Webworm” →

Tree City USA – Online Portal Open, No More Paper Applications!

Posted on by janness

By Laura Buntrock, DNR Urban Forestry Partnership & Policy Specialist, Laura.Buntrock@wisconsin.gov or 608-294-0253

kids holding a Tree City USA bannerThe online portal for Tree City USA (TCUSA) is now open, with applications due Dec. 31. If you’re new to TCUSA, you can learn more about the program on the Arbor Day Foundation’s (ADF) website or from your DNR Urban Forestry Coordinator. Please note that beginning this year, Arbor ADF is no longer accepting paper applications. You can create an account by clicking “sign up now” on the application portal login page. Within the online portal, you will have access to your historical data. More information is available on ADF’s FAQ page. Continue reading “Tree City USA – Online Portal Open, No More Paper Applications!” →

Reminder: Urban Forestry Council Award Nominations Due Oct. 31

Posted on by janness

Governor Tony Evers poses with award winnersDo you know of a person or organization that is making a difference in community forestry? Maybe it is a volunteer who spends their free time planting trees in the community or an organization that is committed to increasing tree diversity or a municipal employee who has dedicated their career to transforming a city’s urban forestry program. If so, please complete this short online nomination form to recognize them for their efforts! Continue reading “Reminder: Urban Forestry Council Award Nominations Due Oct. 31” →

Don’t Stop Watering Your Trees Yet!

Posted on by janness

By Brian Wahl, DNR Urban Forestry Coordinator, Brian.Wahl@wisconsin.gov or 608-225-7943

A simple act, a science and an art, but bottom line – all trees need water (even in autumn)

It’s a very dry start to autumn this year. Heck, it’s been a dry second half of summer, but thanks to our lovely wet spring, we aren’t in a drought yet. However, areas of the state are “abnormally dry” according to the U.S. Drought Monitor. So be sure to get out there and water your newly planted trees! If you have the time, your established trees would appreciate a cool drink of H20 as well.

screenshot of WI drought map

Continue reading “Don’t Stop Watering Your Trees Yet!” →

Program Spotlight: DNR’s Inflation Reduction Act Funded Projects Taking Root

Posted on by janness

By Jay Dampier, DNR IRA Grant Coordinator, Jason.Dampier@wisconsin.gov or 920-765-1935

a newly planted tree in front of a municipal building

A tree planted with IRA funds is poised to provide shade over the parking lot at Mᶏᶏnᶏᶏpe Hocira – Ho-Chunk Veterans Housing Complex.

On a crisp spring morning in 2025, shovels break ground along a city street in Wisconsin. In another community, trees are being inventoried and assessed for risk. Elsewhere, a dangerous dead ash tree is being removed with a crane to make a neighborhood safer. It’s all part of a bold, three-year initiative made possible through the Inflation Reduction Act (IRA) and administered by the DNR’s Urban and Community Forestry Program. One year in, the thirteen grant-funded projects totaling $4 million are already taking root. Grantees include municipalities, tribes, nonprofits and one county. Grant awards range from under $100,000 to nearly $500,000 and are helping communities grow healthier, greener and more resilient. Together, these efforts are transforming neighborhoods and creating a legacy of shade, clean air and beautification across Wisconsin. Continue reading “Program Spotlight: DNR’s Inflation Reduction Act Funded Projects Taking Root” →