Care for your woods

White Pine Blister Rust Can Devastate Young Stands

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

A close-up photo of a white pine blister rust canker as seen on a young white pine tree.

A white pine blister rust canker as seen on a young white pine tree. / Photo Credit: Wisconsin DNR

Eastern white pine (Pinus strobus) has historically held great ecological, cultural and economic value throughout Wisconsin, a tradition which continues today. For more than 100 years, however, it has been threatened by a non-native, invasive fungal pathogen called Cronartium ribicola, or white pine blister rust (WPBR).

Continue reading “White Pine Blister Rust Can Devastate Young Stands”

Watch For Woodpecker Damage On Ash Trees

Woodpecker flecking on the bark of a dying ash tree is visible at Winnebago County Community Park in Oshkosh.

Woodpecker flecking on the bark of a dying ash tree is visible at Winnebago County Community Park in Oshkosh. Flecking occurs when the birds peck away at the trees to feed on emerald ash borer larvae beneath the bark. / Photo Credit: Wisconsin DNR

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

The Wisconsin Department of Natural Resources (DNR) encourages property owners to watch for woodpecker damage to their ash trees this winter.

Woodpecker damage, often called “flecking,” happens when birds peck away some of a tree’s bark to access the larvae underneath. Flecking is a common early sign that an ash tree might be infested with emerald ash borer (EAB), an invasive insect. EAB is the most damaging threat to Wisconsin trees, killing more than 99% of the untreated ash trees it infests.

Continue reading “Watch For Woodpecker Damage On Ash Trees”

Arbor Day Seedling Orders Open To Fourth-graders

By Wisconsin DNR

A worker plants a red pine seedling provided by the Wisconsin Department of Natural Resources.

A worker plants a red pine seedling provided by the Wisconsin Department of Natural Resources. / Photo Credit: Wisconsin DNR

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 “Arbor Day Seedling Orders Open To Fourth-graders”

DNR Urban Forestry Grant Update

The 2026 Urban Forestry Grant application deadline was Oct. 1, 2025, and the Wisconsin Department of Natural Resources (DNR) received 71 applications, equaling over $1.1 million in funding requests. A total of $559,680 is available in grant funding for 2026.

Cities, villages, towns, counties, tribes and 501(c)(3) nonprofit organizations in or conducting their project in Wisconsin are eligible to apply for an Urban Forestry Grant. The grants range from $1,000 to $25,000, and grant applicants must match each grant dollar for dollar. Grants are awarded to projects that align with state and national goals for increasing the urban forest canopy and the benefits it provides. Continue reading “DNR Urban Forestry Grant Update”

Go-To Online Resources For Urban Forestry

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”

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

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

*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

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

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”

Take Advantage Of Mild Winter Days To Prune Trees

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”