Woodland owners

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.

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DNR Tree And Shrub Seedling Sales To Begin Oct. 6

The Wisconsin Department of Natural Resources (DNR) is accepting seedling orders from Wisconsin landowners for trees and shrubs to be planted in spring 2026, starting Oct. 6, 2025.

Wisconsin forest nurseries have provided high-quality, native tree seedlings, appropriate for planting throughout Wisconsin, for over 100 years. Seedlings grown at the state nurseries are used for reforestation and conservation plantings on private, industrial, tribal and public lands. Continue reading “DNR Tree And Shrub Seedling Sales To Begin Oct. 6”

Bur Oak Blight Confirmed In Calumet County

Photo of a wedge-shaped area of dead tissue at the tip of a bur oak leaf from a tree infected with bur oak blight.

A wedge-shaped area of dead tissue at the tip of a bur oak leaf from a tree infected with bur oak blight. / Photo Credit: Wisconsin DNR

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

Recent laboratory examination has confirmed the presence of bur oak blight in Calumet County. The disease affects only bur oaks and is caused by the fungus, Tubakia iowensis.

Calumet County is the 35th Wisconsin county to have a confirmed detection of bur oak blight. The disease has not been microscopically confirmed in all counties where bur oak grows and is likely present in additional counties. Bur oak blight was first reported in Midwestern states in the 1990s.

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HRD Conks Found In Different Shapes And Sizes

Photo from above showing Heterobasidion root disease growing from an infected tree stump.

Heterobasidion root disease grows from an infected tree stump. / Photo Credit: Wisconsin DNR

By Kyoko Scanlon, DNR Forest Pathologist, Fitchburg
Kyoko.Scanlon@wisconsin.gov

Fall is a great time to look for mushrooms, including conks from trees infested with Heterobasidion root disease (HRD).

Considered one of the most destructive diseases of conifers in the northern hemisphere, the fungus causing HRD is very difficult to eradicate once established. Infestation of a conifer stand may significantly impact stand management, making early detection of the disease extremely important.

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Invasive Japanese Stiltgrass Detected In Three More Counties

Wide-angle photo of a mat of Japanese stiltgrass in Rock County, Wisconsin, in July 2025

A mat of Japanese stiltgrass in Rock County, Wisconsin, in July 2025. / Photo Credit: John Zaborsky, University of Wisconsin-Madison Renz Weed Science Lab

By Wisconsin DNR

Thanks to the help of eagle-eyed observers across southern Wisconsin, the harmful invasive plant Japanese stiltgrass (Microstegium vimineum) has now been detected in three additional counties. That brings the total number of Wisconsin counties to five.

The most recent detections of the non-native, annual grass came in Dane, Grant and Walworth counties. The Dane County find was in Middleton, northwest of Madison; in Grant County, it was found southeast of Wyalusing State Park; in Walworth County, it was found north of Geneva Lake.

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Autumn Is A Great Time To Treat Invasive Plants

By Wisconsin DNR

Photo of rosettes on a garlic mustard plant. / Photo Credit: Wisconsin DNR

Rosettes on a garlic mustard plant. / Photo Credit: Wisconsin DNR

As temperatures begin to fall the leaves of many plants and trees have begun to change color. Some trees in the northern part of the state have already started to drop their leaves.

The Wisconsin Department of Natural Resources (DNR) reminds the public that fall is more than a great time to enjoy the changing hues in the woods. It also presents a good opportunity to spot the invasive plants persisting among the native plants and trees.

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The DNR Reforestation Program Needs Seeds

By Jeremiah Auer, DNR Regeneration Specialist; Jeremiah.Auer@wisconsin.gov

The DNR’s Reforestation Program needs red and white pine cones – more specifically, we need the seeds found within those cones for our reforestation needs. The Reforestation Program produces millions of pine seedlings every year at the Wilson State Nursery in Boscobel, and the only way we can produce those seedlings is with seed collected from the fields and forests of Wisconsin. Continue reading “The DNR Reforestation Program Needs Seeds”

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, including Z133 updates, urban tree lifespan, maintaining urban trees on private lands, conferences and watering. Continue reading “Upcoming Trainings”

Woodland Owners Group And MFL Keep Forests Growing

By Art Kabelowsky, DNR Outreach and Communications, Fitchburg Arthur.Kabelowsky@wisconsin.gov; 608-335-0167

Nancy Bozek (far right), executive director of the Wisconsin Woodland Owners Association (WWOA), joins the Women of WWOA group for a photo after a guided tour of the International Crane Foundation outside of Baraboo.

Nancy Bozek (far right), executive director of the Wisconsin Woodland Owners Association (WWOA), joins the Women of WWOA group for a photo after a guided tour of the International Crane Foundation outside of Baraboo. / Photo Credit: Contributed by Nancy Bozek

There are plenty of trees in Wisconsin forests that haven’t been around as long as the Wisconsin Woodland Owners Association (WWOA).

In many cases, the 46-year-old WWOA has facilitated the information sharing, networking and hard work necessary to keep as many of those trees as possible, along with the older ones, of course, green and growing.

WWOA’s mission statement is one of those simple ideas that needs a lot of effort to become reality: “(T)o conserve and enhance the private woodlands of the state through the following actions:

  • Sustainably manage our woodlands with informed management plans that utilize best silviculture practices.
  • Assist private landowners in achieving their management goals by connecting them with natural resource professionals and fellow woodland owners.
  • Educate the public on the value of woodlands for economic, environmental, recreational and wildlife habitat purposes.”

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Maple Petiole Borer Sawfly Causing Leaf Drop

A closeup display photo showing prematurely fallen sugar maple leaves that have a normal appearance, except for characteristic darkened petiole stubs caused from feeding damage of the maple petiole borer.

Prematurely fallen sugar maple leaves with normal appearance except for characteristic darkened petiole stubs caused from feeding damage of the maple petiole borer. / Photo Credit: Paul Cigan, Wisconsin DNR

By Paul Cigan, DNR Forest Health Specialist
Paul.Cigan@wisconsin.gov or 715-416-4920

Fallen maple leaves have been observed under Wisconsin maple trees since late May.

The fallen leaves are typically of normal shape, size and color, but have a darkened petiole stub (i.e., leaf stem) remaining. A closer examination of the petiole may reveal a hollow feeding tunnel containing tiny larvae of the insect responsible for the damage inside: the maple petiole borer.

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