Woodland owners

DNR Urges Spring Spongy Moth Treatment Plans

Carefully scraping spongy moth egg masses off trees and into a cup of soapy water will help to hold down caterpillar damage in 2025.

Carefully scraping spongy moth egg masses off trees and into a cup of soapy water will help to hold down caterpillar damage in 2025. / Photo Credit: Bill McNee, Wisconsin DNR

By Bill McNee, DNR Forest Health Specialist
Bill.McNee@wisconsin.gov
or 920-360-0942

The Wisconsin Department of Natural Resources (DNR) encourages property owners to examine their trees for spongy moth egg masses and determine whether control measures are needed this spring.

Property owners who have oak, birch, crabapple, aspen, willow and linden (basswood) trees should be particularly watchful because the caterpillars of this invasive insect prefer these species. However, they will feed on many other kinds of trees and shrubs.

Continue reading “DNR Urges Spring Spongy Moth Treatment Plans”

Spring Brings Opportunities To Protect Oak Trees

A photo of an oak tree with a branch that has been pruned, but not treated with protective paint to prevent infection with oak wilt.

Pruning, cutting, or wounding oaks during April through July leaves them vulnerable to oak wilt. / Photo Credit: Paul Cigan, Wisconsin DNR

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

With warmer spring weather fast approaching, the Wisconsin Department of Natural Resources (DNR) recommends protecting oaks from the often-fatal disease, oak wilt, by refraining from pruning, cutting or injuring oak trees from April through July.

Oak wilt is a serious disease that kills trees in the red oak group (including pin oak, northern red oak and black oak) and weakens those in the white oak group (bur oak, swamp white oak, white oak and English oak).

Continue reading “Spring Brings Opportunities To Protect Oak Trees”

Squirrels Can Damage Trees During Late Winter

Photo showing that squirrels have removed significant amounts of bark from a maple tree's trunk to get at the tasty cambium layer underneath.

Squirrels have removed significant amounts of bark from this maple to get at the tasty cambium layer underneath. / Photo Credit: Linda Williams, Wisconsin DNR

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

Squirrels can be fun to feed and fun to watch, but when they start damaging or killing your trees, well, that’s not so cute.

It’s the time of year when we start to have some warm days that allow sap to start moving in trees. If there are broken branches or damaged bark, the tree can drip sap. And that can attract squirrels.

Continue reading “Squirrels Can Damage Trees During Late Winter”

Make Plans Now To Fight Spongy Moth In 2025

A photo showing large egg masses on a tree at the Kettle Moraine State Forest-Southern Unit in 2021.

Large egg masses are seen on a tree at the Kettle Moraine State Forest-Southern Unit in 2021. / Photo Credit: Bill McNee, Wisconsin DNR

By Bill McNee, DNR Forest Health Specialist, Oshkosh
Bill.McNee@wisconsin.gov or 920-360-0942

Part Two of a report on spongy moth in Wisconsin in 2024 and 2025. Part One was published in December.

The Wisconsin Department of Natural Resources (DNR) is encouraging property owners to examine their property for spongy moth egg masses and plan for action this spring if needed. Each spongy moth egg mass contains hundreds of eggs that will hatch into hungry, leaf-eating caterpillars this spring. Large numbers of these invasive caterpillars can be a tremendous nuisance that may cause tree mortality.

Continue reading “Make Plans Now To Fight Spongy Moth In 2025”

Tree Disease Maps Have Migrated

The Wisconsin web map for Heterobasidion root disease, available through ArcGIS Online.

The Wisconsin web map for Heterobasidion root disease, available through ArcGIS Online. / Map Credit: Paul Cigan, Wisconsin DNR

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

The Wisconsin Department of Natural Resources (DNR) Forest Health program hosts two interactive web maps on its webpage:

Heterobasidion Root Disease

Oak Wilt Seasonal Harvesting Opportunities

Continue reading “Tree Disease Maps Have Migrated”

McNee To Speak At Green Bay Conference

Photo showing a few periodical cicadas trying to hitch a ride on the T-shirt of Bill McNee, the Wisconsin Department of Natural Resources Forest Health specialist for northeast Wisconsin, in 2024 at Big Foot Beach State Park in Lake Geneva.

A few periodical cicadas try to hitch a ride on the T-shirt of Bill McNee, the Wisconsin Department of Natural Resources forest health specialist for northeast Wisconsin, at Big Foot Beach State Park in Lake Geneva in 2024. / Photo Credit: Wisconsin DNR

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

Bill McNee, the Wisconsin Department of Natural Resources (DNR) forest health specialist for the Southeast region, will give a public presentation on Saturday, Jan. 25, at the Green Bay Winter Landowner Conference.

Continue reading “McNee To Speak At Green Bay Conference”

Please Submit Trees Planted This Year!

By Dan Buckler, DNR Urban Forest Assessment Specialist; Daniel.Buckler@wisconsin.gov or 608-445-4578

Autumn is a wonderful time for planting trees. And after the trees go in the ground, please take a few minutes to document the effort in the Wisconsin Tree Planting Map. The map was designed to help track trees planted to advance the state’s pledge to the Trillion Trees Initiative.

Continue reading “Please Submit Trees Planted This Year!”

2024 Spongy Moth Review

By Bill McNee, DNR Forest Health Specialist, Oshkosh;
Bill.McNee@wisconsin.gov or 920-360-0942

A tree shows high numbers of spongy moth caterpillars, though the majority of the caterpillars have been killed either by virus (hanging in an inverted V) or fungus (hanging in a stretched line, head down). The virus and fungus helped to quell a potential outbreak in many areas of the state in 2024.

A tree shows high numbers of spongy moth caterpillars, though the majority of the caterpillars have been killed either by virus (hanging in an inverted V) or fungus (hanging in a stretched line, head down). The virus and fungus helped to quell a potential outbreak in many areas of the state in 2024. / Photo Credit: Bill McNee, Wisconsin DNR

As the 2023 spongy moth season ended, there were hopes for a return to colder and wetter conditions in 2024 so that the spongy moth outbreak would decline or even come to an end.

What wound up happening in Wisconsin was the “lost winter,” the warmest since recordkeeping began in 1895. Given this warmth, there were concerns that the widespread spongy moth outbreak would continue for a third consecutive summer, with good caterpillar survival, ongoing defoliation and high rates of tree mortality in already stressed forests.

Continue reading “2024 Spongy Moth Review”

Cooperative Enlists Public To Make Tree Health A Snap

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

Screenshot of the main page of the TreeSnap app as seen on a mobile phone.

The main page of the TreeSnap app as seen on a mobile phone. / Photo Credit: TreeSnap.org

It takes more than a village to foster healthy forests. More than a township, a city and a county, too. Sometimes, even more than a state.

That’s why the Great Lakes Basin Forest Health Cooperative (GLB FHC) was formed four years ago by Holden Arboretum in Ohio and the U.S. Department of Agriculture Forest Service.

Geographically, the group’s region encompasses an area from New Jersey to Wisconsin. The Wisconsin Department of Natural Resources (DNR) is an active member.

Continue reading “Cooperative Enlists Public To Make Tree Health A Snap”

Forest Health and Climate Change Resources

By Carmen Hardin, Director, DNR Applied Forestry Bureau, Rhinelander;
Carmen.Hardin@wisconsin.gov

A graphic shows changing tornado risk trends in the United States from 1980 to 2020. All Wisconsin counties are showing an increase in tornado days.

A graphic shows changing tornado risk trends in the United States from 1980 to 2020. All Wisconsin counties are showing an increase in tornado days. / Map Credit: Inside Climate News, Stephen M. Strader et. al., Nature Magazine

We are often asked difficult questions about our forests, their health and how climate change is impacting them. Here is a curated collection of resources that may help you answer some of those questions. Continue reading “Forest Health and Climate Change Resources”