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Oak Wilt Information Updated

University of Wisconsin-Madison Extension online tool to help with oak wilt decisions.

A University of Wisconsin-Madison Extension online tool provides users localized information about the estimated emergence status of the two most important insects that transmit oak wilt in Wisconsin. / Graphic Credit: University of Wisconsin-Madison Extension

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

In 2025, oak wilt was detected for the first time in Hughes Township, Bayfield County, a northern Wisconsin location where oak wilt remains uncommon. There were no new county finds in 2025.

Based on the findings in 2025, the maps in the Oak Harvesting Guidelines To Reduce The Risk Of Introduction And Spread Of Oak Wilt (the oak wilt guidelines), oak wilt fact sheet and were updated. The maps in the oak wilt guidelines are good through the end of 2026.

Continue reading “Oak Wilt Information Updated”

Stilt Grass StoryMap Updated For 2026

Main page of the Wisconsin DNR's StoryMap on Japanese stilt grass.

The main page of the Wisconsin Department of Natural Resources’ StoryMap titled “Japanese Stilt Grass on the Coulee Experimental State Forest.” / Graphic Credit: Wisconsin DNR

By Carter Hellenbrand, DNR Invasive Plant Field Specialist, Fitchburg
Carter.Hellenbrand@wisconsin.gov

The Wisconsin Department of Natural Resources (DNR) Forest Health program has updated the Japanese stilt grass StoryMap to reflect all the work completed in 2025. The StoryMap documents the history of this invasive species on the Coulee Experimental State Forest in La Crosse County.

A StoryMap is a web-based content creation and communication tool that allows creators to share maps, apps and multimedia in the context of a narrative. Users can see an overview of Japanese stilt grass, how to identify it and what control efforts have been implemented since the plant was first detected in Wisconsin in 2020.

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Oak Wilt High Risk Period Quickly Approaches

A closeup of a fungal pressure pad under the bark of an oak tree infected with oak wilt.

A fungal pressure pad formed on the outside of the sapwood underneath the bark of an infected tree. The pad will create cracks in the bark, where beetles can enter and visit the pad and become covered in spores. They will then leave and move on to infect new trees through open wounds. / Photo Credit: Wisconsin DNR

By Alex Hornung, DNR Forest Health Specialist, Plover
Alexandra.Hornung@wisconsin.gov or 715-340-3810

It is again that time of year to pause operating in oak stands or pruning oak trees during the high-risk period for oak wilt, which begins in April. The high-risk period begins April 1 in the South, April 15 in the North, and ends in both zones on July 15.

The high-risk period is determined by when the beetles that carry the fungus that causes oak wilt have emerged for the year and when they are carrying the highest number of fungal spores. When wounds are created by logging operations or other activities that expose sapwood, the beetles carry the fungus to the wounded tree, and the disease process begins.

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Watch For Squirrel, Porcupine Damage In Spring

Closeup of small squirrel tooth marks on a tree's mainstem.

Squirrel tooth marks are small and look like narrow scratches from which the animals have removed the tree’s bark. / Photo Credit: Wisconsin DNR

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

As winter transitions into spring, you may notice patches of tree bark that have been removed. But what did the damage?

Several animals, including squirrels and porcupines, can chew or strip bark from trees. This can occur on hardwoods and conifers, older trees and young saplings. Damage can be enough to kill branches or even the entire tree.

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Does Cold Weather Bug The Bugs?

A map of Wisconsin showing cold temperatures on Jan. 25, 2026.

Cold temperatures across the state of Wisconsin on Jan. 25, 2026. / Graphic Credit: National Weather Service

By River Mathieu, DNR Forest Health Specialist, Fitchburg
River.Mathieu@wisconsin.gov or 608-772-2758

Wisconsin experienced a polar vortex in late January 2026, and temperatures got chilly throughout the state, even reaching close to -40⁰ F in some places! Although it has warmed up, the cold weather is still fresh in everyone’s minds, leaving insect and forest lovers alike wondering how insects survive temperatures that cold.

The Wisconsin Department of Natural Resources Forest Health staff has received several questions over the past month about how insects survive cold weather in winter and whether the January temperatures were cold enough to kill insect pests.

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Wisconsin’s Urban Forestry Council 2025 Biennial Report Published

By Jenn Janness, Urban Forestry Council Liaison
Jennipher.Janness@wisconsin.gov or 920-809-9330

2025 report coverThe purpose of the Wisconsin Urban Forestry Council is to advise the state forester and the Wisconsin DNR on the best ways to preserve, protect, expand and improve Wisconsin’s urban and community forest resources. Members are appointed by the DNR Secretary and represent a wide array of stakeholders, including municipal and utility foresters, medical and higher education professionals, nursery and green industry staff, environmental groups, public works and parks staff, organizations such as the Wisconsin Arborist Association (WAA), the Urban Wood Network Wisconsin, the League of Wisconsin Municipalities and government agencies such as WisDOT and DATCP. Continue reading “Wisconsin’s Urban Forestry Council 2025 Biennial Report Published”

LEAF Lessons

Leaf websiteArbor Day is right around the corner, but why wait to start celebrating and learning about trees? The LEAF K-12 Forestry Education Program provides resources to incorporate into the classroom for Arbor Day or any day! The downloadable Urban Forest Lesson Guide provides a pathway for teachers to engage students and teach them about the trees in their neighborhood. Forestry Education Kits on a variety of different themes are also available for checkout for both formal and non-formal educators. Check out the LEAF website and consider utilizing the resources they have to offer this spring. Continue reading “LEAF Lessons”

Tree Fund Scholarships And Grant Deadline March 15, 2025

Tree FundTREE Fund offers scholarships for undergraduate students who aspire to careers in arboriculture, urban forestry and related fields. Before applying for any scholarship, carefully read the guidelines for each scholarship provided on the website. Contact a staff member at TREE Fund directly should you have questions or require additional information about these programs.

Apply online by March 15, 2026. Continue reading “Tree Fund Scholarships And Grant Deadline March 15, 2025”

USDA Forest Service Requests Proposals for Wood Innovations Grants

A stack of logs

A stack of logs guards an old conifer seed orchard near Lake Tomahawk in the Town of Hazelhurst in 2024. / Photo Credit: Wisconsin DNR

By United States Department of Agriculture Forest Service

The United States Department of Agriculture’s Forest Service today announced up to $95 million in competitive grant funding through its Wood Innovations program for projects that advance innovative wood uses, expand wood-based construction, and grow U.S. wood energy markets and forest product processing capacity.

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