Care for your woods

Look For Spongy Moth Egg Masses – Larger Outbreak Possible in 2023

Posted on by kirsten.biefeld

By: Bill McNee, DNR Forest Health Specialist, Oshkosh

bill.mcnee@wisconsin.gov or 920-360-0942

Three tan-colored spongy moth egg masses on a single tree branch in Walworth County.

Three spongy moth egg masses on a branch in Walworth County. Photo Credit: Bill McNee, Wisconsin DNR

Now that spongy moth* (formerly known as gypsy moth) egg laying is complete for 2022, it’s a good time to look for and dispose of egg masses produced by adult moths over the past two months.

Spongy moth egg masses are tan-colored lumps about the size of a nickel or quarter, and are found on trees, buildings and other outdoor objects. They may also be found in protected places such as firewood piles and birdhouses. Newly produced egg masses will feel firm and appear darker in color than older egg masses, which appear faded, feel spongy and do not contain viable eggs. The current-year egg masses will not hatch until next spring.

In 2022, Wisconsin’s spongy moth population grew for a third consecutive summer due to favorable weather conditions and limited caterpillar mortality from diseases. The outbreak was most dramatic in opposite ends of the state. In southern and southeast Wisconsin, several thousand oak-dominated acres were heavily defoliated and very large numbers of property owner reports were received by DNR staff. In Bayfield County, about 80,000 acres of rural defoliation was reported from aspen-dominated forests. Smaller patches of defoliation were also reported from several other counties. Continue reading “Look For Spongy Moth Egg Masses – Larger Outbreak Possible in 2023” →

Trees Will Need More Water this Summer

Posted on by patricialindquist

We are likely to see a hotter than average summer, which means you, your pets, your plants, and yes, your trees, will need more water!

Stress from drought can affect all plants, from a newly planted sapling to a well-established, mature tree. Trees that are already weakened from other types of stress, such as tree leaf predation by spongy moths, are of particular concern.

See our watering tips below for how you can help!

Continue reading “Trees Will Need More Water this Summer” →

White Trunk Rot In Aspen Trees

Posted on by brenna.denamur

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

White trunk rot (Phellinus tremulae), sometimes called aspen trunk rot, is a fungus that causes decay columns to form in aspen. The fungus enters the tree through branch stubs, wounds or small dead branches that remain on the tree. Perennial conks, or fungal bodies, then grow from these sites.

A cross section of the trunk of an aspen with significant decay in the center and a fruiting body conk on the side of the wood.

White trunk rot causes decay in aspen trees. Note the conk (fruiting body) from the fungus on the left side of the pic. Photo: Wisconsin DNR

Continue reading “White Trunk Rot In Aspen Trees” →

EAB Identified For The First Time In Forest And Ashland County

Posted on by brenna.denamur

By Linda Williams, DNR Forest Health Specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665 & Paul Cigan, DNR Forest Health Specialist, Hayward, Paul.Cigan@wisconsin.gov, 715-416-4920

Emerald ash borer (EAB) has been detected for the first time in Forest County in the Town of Armstrong Creek and Ashland County in the City of Ashland. The Forest County detection was most likely a natural expansion of other infestations in Florence and Marinette counties.

Bark has been removed from an ash tree to show EAB tunnels present near the base of the tree.

This Forest County tree was infested with EAB top to bottom. Photo: Wisconsin DNR

The Ashland County detections appear to be isolated infestations likely spread through the transportation of firewood or logs. Several large green ash stands in the City of Ashland show advanced infestation signs.

EAB was first found in Wisconsin in 2008. There are now just seven counties where EAB has not yet been identified. EAB was federally deregulated as of January 2021. In 2018, Wisconsin instituted a state-wide quarantine. This discovery in Forest and Ashland counties will result in no regulatory changes.

Please visit the interactive Wisconsin EAB detections map to see where EAB has been reported. Follow the map’s instructions if you know of an infested area not on the map. Continue reading “EAB Identified For The First Time In Forest And Ashland County” →

Spring Cleaning: Storm Damage Cleanup Brings Oak Wilt Risk

Posted on by brenna.denamur

By Linda Williams, DNR Forest Health Specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665 & Paul Cigan, DNR Forest Health Specialist, Hayward, Paul.Cigan@wisconsin.gov, 715-416-4920.

Spring cleanup is always a busy time in the Northwoods as those with second homes and cabins make the trek northward to prepare for a summer of fun. For many, this will mean cleaning up trees and branches damaged by winter storms.

A forested scene with broken branches at the base of a white pine tree.

Large white pines (pictured here) and young birch growing on forest edges were most heavily impacted by winter’s storms. Photo: Wisconsin DNR

Continue reading “Spring Cleaning: Storm Damage Cleanup Brings Oak Wilt Risk” →

April Showers Bring May Garlic Mustard

Posted on by brenna.denamur

By Brenna DeNamur, DNR Forest Health Outreach Specialist, Madison, Brenna.DeNamur@wisconsin.gov; Jaqi Christopher, DNR Forest Invasive Plant Specialist, Rhinelander, Jacquelyn.Christopher@wisconsin.gov; & Mary Bartkowiak, DNR Forest Invasive Plant Coordinator, Rhinelander, Mary.Bartkowiak@wisconsin.gov

Spring is here! Invasive plants, like garlic mustard, are often among the first green life to emerge in the new season.

A dense population of garlic mustard carpets a forest floor.

Garlic mustard is an invasive plant that appears early in spring. Photo: Wisconsin DNR

Continue reading “April Showers Bring May Garlic Mustard” →

Species Recommendations Available

Posted on by patricialindquist

If you’re reading this, you love trees and have no doubt been asked for your tree species recommendations. The Wisconsin Department of Natural Resources (DNR) Urban Forestry Program is no different. Because species recommendations are an evergreen request, we developed four lists, accounting for a small number of large and small trees in street and park environments.

These lists are not exhaustive (only ten species in each) and any general list of recommendations is somewhat fraught with uncertainty due to the nuanced conditions of specific planting sites. We highly suggest consulting with your local nurseries and other experts who can not only discuss what is available but also provide other recommendations and planting advice. With just a few exceptions, these lists do not include cultivars and varieties, but your local experts can provide that amount of detail.

Continue reading “Species Recommendations Available” →

Rochester Creates Arboretum To Encourage Species Diversity

Posted on by patricialindquist

By Sara Minkoff, retired DNR Urban Forestry Council Liaison

Many smaller Wisconsin communities would like to expand their tree planting efforts but have limited budgets. One village in southern Wisconsin came up with a solution.

Rochester Commons Park has been working to create an arboretum using several grants from the American Transmission Company, an electric transmission utility that aids in promoting natural resources in areas separate from electrical utility service lines.

The western Racine County village of about 4,000 people is lined predominantly with maple trees in the public right-of-way along streets and sidewalks. The goals of the ATC-funded project are to exhibit a variety of species beyond the maples to encourage residents to plant and grow more types of trees and diversify and beautify Rochester.

Continue reading “Rochester Creates Arboretum To Encourage Species Diversity” →

Emerald Ash Borer Found In Bayfield County

Posted on by brenna.denamur

By Paul Cigan, DNR Forest Health Specialist

Paul.Cigan@wisconsin.gov or 715-416-4920

Emerald ash borer (EAB) has been discovered in Bayfield County for the first time in both the city of Bayfield and Bayview township to the south. This marks the 63rd out of Wisconsin’s 72 counties to have an EAB discovery since its initial detection in 2008.

Dead white ash with woodpecker damage in a park

Figure 1: First known infested ash tree in Bayfield County with characteristic woodpecker damage (i.e., flecking).
Photo: Wisconsin DNR

Several white ash trees (Fig 1.) were observed in and around a roadside park in the city of Bayfield, and larval specimens were subsequently lab-confirmed. In Bayview, a black ash swamp had several infested black ash (Fig 2). 

After introduction, EAB populations remain low for at least several years as most larvae in newly infested, healthy ash require two years to complete their life cycle. The abundance of healthy ash at each site suggests EAB populations have remained low since their introduction at least three years ago. However, EAB will kill ash more quickly as beetle numbers mount and more larvae transform from egg to adult in a single year. Unfortunately, many ash in the area are expected to die within four to seven years based on detection-to-impact timeframes observed from the Superior and Duluth area and research conducted in midwestern states. Continue reading “Emerald Ash Borer Found In Bayfield County” →

Squirrel Damage Mayhem

Posted on by brenna.denamur

By Linda Williams, DNR Forest Health Specialist, Woodruff

Linda.Williams@wisconsin.gov or 920-360-0665

Finger pointing at tooth marks on the wood of a maple that squirrels stripped of bark.

Narrow grooves are left when squirrels chew the bark off a young tree or a branch.
Photo: Wisconsin DNR

In late winter, it’s common to see tree branches that have been freshly stripped of their bark. Damage can be extensive where entire branches, and sometimes entire small trees, can be stripped of bark. This damage, believe it or not, is from squirrels! While primarily found on sugar maples, you can also find squirrel damage on red maples and the occasional oak. So far this year, the damage has been noted in Langlade, Shawano, Oneida and Vilas Counties. 

On sunny days, the pale wood of branches where the bark has been stripped off stands out in the forest. This type of feeding can remove enough bark to girdle the branches or the main stem, causing the tree to die from that point to the end of the branch. Branches that are not entirely girdled will continue to grow, and callus tissue will begin to grow over the wounds. If branches are nearly girdled, they may leaf out in the spring only to have the leaves suddenly wilt and die as hot weather hits because the tree can’t move enough water to keep the leaves alive. Continue reading “Squirrel Damage Mayhem” →