Go-To Online Resources For Urban Forestry

Posted on by janness

By Allen Pyle, UW-Extension Horticulture Outreach Specialist and Jay Dampier, DNR IRA Grant Coordinator, Jason.Dampier@wisconsin.gov or 920-765-1935

Reliable and up-to-date research-based information is vital for tree care professionals and urban foresters to make sound, scientific management decisions. To make trusted resources more accessible, UW-Extension’s Horticulture Program and Wisconsin DNR’s Urban Forestry Program have developed this curated selection of useful webpages with free information and resources for urban forestry professionals and community tree managers. Continue reading “Go-To Online Resources For Urban Forestry” →

Fourth Grade Arbor Day Seedling Orders Now Open

Posted on by janness

The Wisconsin Department of Natural Resources (DNR) is offering free tree seedlings to every fourth-grade student in Wisconsin as part of its annual Arbor Day tree planting program.

Wisconsin fourth grade principals, teachers and homeschoolers can now place seedling orders and coordinate delivery by completing the 2026 Arbor Day application by March 16, 2026. Continue reading “Fourth Grade Arbor Day Seedling Orders Now Open” →

After The Ice: Urban Forestry’s Role In Community Recovery And Resilience

Posted on by janness

By Lee Mueller, Davey Resource Group, Inc., Kevin Sayers, Michigan Department of Natural Resources and Paul Hickman, Urban Ashes

*Republished with permission from the authors

ice covered street trees

Photo Credit: MI DNR

Cold weather is just around the corner, so now is the time to develop or revisit winter storm response plans. Ice storms are a recurring challenge in the Midwest. Freezing rain can add substantial weight to limbs, causing even healthy trees to snap. Ultimately, events like this can offer opportunities to reassess communities’ approaches to tree management and build stronger, more resilient urban forests. Continue reading “After The Ice: Urban Forestry’s Role In Community Recovery And Resilience” →

Upcoming Trainings

Posted on by janness

*These training opportunities are provided as an information service only and do not constitute an endorsement from the Wisconsin Department of Natural Resources (DNR).

See below for information on training topics and events, including urban wood, invasive species, tree rot and decay, beech leaf disease, connecting people to urban forestry and research presentations on pruning regimens, tree science and solar power. Continue reading “Upcoming Trainings” →

Increased Tree Mortality Seen As Spongy Moth Outbreak Ends

Posted on by akabelowsky
Mature spongy moth larva on a tree at Potawatomi State Park in Door County, July 2025.

Mature spongy moth larva on a tree at Potawatomi State Park in Door County, July 2025. / Photo Credit: Wisconsin DNR

By Bill McNee, DNR Forest Health Specialist, Oshkosh
Bill.McNee@wisconsin.gov  

Wisconsin’s recent period of high spongy moth populations (an “outbreak”) came to an end in 2025, as the remaining known hotspots were aerially sprayed or naturally collapsed. Only a handful of large larvae were observed or reported by property owners.

Spongy moth populations are likely to be low across the state for at least the next few years. However, it is possible that some sites may experience a population increase before then, if local weather conditions are favorable for the insect.

Continue reading “Increased Tree Mortality Seen As Spongy Moth Outbreak Ends” →

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” →