Join Matt Smith, a professional restoration ecologist with over 22 years of experience, for an entirely outside, hands-on field demonstration in pruning, coppicing and tree release for restoration and landscaping. This training will take place on Feb. 23, 2024, at Riveredge Nature Center, Newburg, WI (35 miles north of Milwaukee).
For more information and to register, visit the Riveredge Nature Center website.
Species in the knotweed complex grow very quickly, causing large infestations on roadsides like this one. / Photo Credit: Randy Westbrooks, Invasive Plant Control, Inc., Bugwood.org
By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh Service Center;
Erika.SegersonMueller@wisconsin.gov or 715-492-0391
As you work on your New Year’s resolutions this year, you might want to add “don’t plant invasive species” to your list. Too wide-ranging? Try narrowing the goal to a species-specific suggestion: “Just say ‘no’ to knotweeds.”
Sometimes referred to as “the knotweed complex,” Wisconsin has three regulated species of knotweed: Japanese knotweed, giant knotweed and a hybridization known as Bohemian knotweed. Each has been found in the state.
Discolored fallen leaves from a red oak tree indicate that the tree is infected with oak wilt. / Photo Credit: Wisconsin DNR
By Art Kabelowsky, DNR Forest Health Outreach and Communications, Fitchburg Service Center;
Arthur.Kabelowsky@wisconsin.gov or 608-335-0167
With the weather taking its time to turn wintry, it’s a good time to remind landowners and work crews that now through the end of March is an ideal time to perform pruning, trimming and brush removal on and near oak trees.
This is a low-risk period for the trees to be infected with oak wilt, a fungal disease spread by beetles. When a red oak is infected with oak wilt, it will die that year. The disease also stresses white oaks, often proving fatal.
By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh Service Center;
Erika.SegersonMueller@wisconsin.gov or 715-492-0391
A field day in August 2023, hosted by Monroe County Invasive Species Working Group, featured a live goat grazing demonstration among presentations that included invasive plant identification tips, funding opportunities and management techniques. / Photo Credit: Wisconsin DNR
If you’ve been fighting invasive plants in your woodlands, you may have wondered if there were any groups in your area to support weed management. The short answer? Probably!
Wisconsin currently has 14 different Cooperative Invasive Species Management Areas, or CISMAs. These regional county groups bring together community members to work on various invasive species-related projects ranging from fieldwork outings to controlling and monitoring invasive plant occurrences to education and outreach events so more local citizens can learn about and get involved with invasive plant management.
The pith of invasive honeysuckle, seen here, is brown and hollow. / Photo Credit: Chris Evans, University of Illinois, Bugwood.org
By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh;
Erika.SegersonMueller@wisconsin.gov or 715-492-0391
They may have sweet-sounding names, but Eurasian bush honeysuckles (Lonicera spp.) can bring a bitter taste to your mouth if found in your woodlands.
Originating as horticultural plantings, this group of upright woody shrubs is now widespread in Wisconsin and the upper Midwest.
Invasive honeysuckle shrubs are among the earliest plants to leaf out in the spring and the last to lose their leaves in the fall. This extended growing season allows them to outcompete other plants for nutrients and sunlight, casting dense shade on the forest floor.
Native honeysuckles are also present in Wisconsin. Several identifying characteristics can help you determine if your honeysuckle is a native species or one of the invasive varieties. When in bloom, the flowers of invasive Bell’s, Morrow’s and Tartarian honeysuckles are easily distinguished. Without the blooms, the easiest methods to determine non-native honeysuckle from the native plant include looking for shaggy, peeling gray-brown bark and checking the pith.
The pith (inner tissue of the branches and stems) can be observed by breaking off an older branch. If the pith appears white, the shrub is native honeysuckle. If the pith is brown and hollow, it is likely one of the invasive bush versions.
Winter is a great time to treat invasive honeysuckle shrubs on your property since most other plants have gone dormant for the season. Winter herbicide applications are highly successful on freshly cut stumps, provided snow does not cover the cut surface. Basal bark applications may also be used on snow-free surfaces.
Stump cutting should be followed by herbicide treatments, as vigorous resprouting may occur from shrubs cut in winter but not treated with herbicide. Learn more about invasive honeysuckles and how to manage them on the Bush honeysuckles fact sheet from Renz Weed Science at the University of Wisconsin-Extension.
A finger points to a tan-colored spongy moth egg mass on a tree. / Photo Credit: Bill McNee, Wisconsin DNR
By Bill McNee, DNR Forest Health Specialist, Oshkosh;
Bill.McNee@wisconsin.gov or 920-360-0942
If the 2024 spring and summer weather conditions are favorable for the spongy moth (Lymantria dispar) population, the current outbreak will continue and spread to other parts of Wisconsin. Property owners are encouraged to examine susceptible host trees (including oak, birch, crabapple, aspen and willow) and make plans to manage them.
In summer 2023, Wisconsin saw a record amount of defoliation. State agencies received many calls from property owners urgently seeking a tree care business to control a large caterpillar infestation.
Continue reading “Make Your 2024 Spongy Moth Treatment Plans Early”
Numerous spongy moth egg masses on an oak tree in Walworth County. / Photo Credit: Bill McNee, Wisconsin DNR
By Bill McNee, DNR Forest Health Specialist, Oshkosh;
Bill.McNee@wisconsin.gov or 920-360-0942
Forest managers planning silvicultural treatments in stands susceptible to spongy moth (Lymantria dispar) – such as those containing many host species, including oak, birch, aspen and basswood – are encouraged to conduct annual egg mass surveys before treatment.
Surveys make it possible to predict if heavy defoliation is likely. If more than 30 egg masses are found in a sample area – a circle with a 37-foot diameter – then heavy defoliation is expected in the spring, and management activities should be altered or delayed until an outbreak has ended. Continue reading “Harvest Timing Affected By Spongy Moth”
With the addition of Ashland County, oak wilt has now been detected in 66 of Wisconsin’s 72 counties. / Map Credit: Wisconsin DNR.
By Paul Cigan, DNR Forest Health Specialist, Hayward
Paul.Cigan@wisconsin.gov or 715-416-4920
Oak wilt, a deadly disease of oaks, has been found for the first time in Ashland County.
The Wisconsin Department of Natural Resources (DNR) confirmed the find in wood samples from a red oak tree in the town of Gordon.
“There is always risk of oak wilt spread into new and relatively uninfested areas in northern Wisconsin, such as Ashland County, so it’s always best to practice oak wilt prevention wherever possible to significantly reduce that risk,” said Paul Cigan, a DNR forest health specialist based in Hayward.
A pair of spongy moth egg masses attached to a piece of firewood. Moving this firewood to another site could put trees at that site at risk in the spring. / Photo Credit: Wisconsin DNR
By Art Kabelowsky, DNR Forest Health Outreach/Communications
Arthur.Kabelowsky@wisconsin.gov or 608-335-0167
Are you generally hesitant to give hitchhikers a free ride?
October was National Firewood Awareness Month, and even though November has arrived, the Wisconsin Department of Natural Resources (DNR) continues to urge residents and visitors to follow the same line of thinking when it comes to moving firewood.
That’s because tree-killing hitchhikers often lurk on or in firewood — including spongy moth, emerald ash borer, the fungus that causes oak wilt and other invasive insects and fungi. When untreated, infested firewood is transported away from where the tree died, those pests and fungi can later emerge to attack trees at the new site. This can happen whether that new location is in the next town or hundreds of miles away.
Continue reading “Don’t Let Tree Trouble Hitch A Ride On Firewood”
A bur oak more than 100 years old exhibits canopy dieback and epicormic branching caused by twolined chestnut borer. / Photo Credit: Wisconsin DNR
By Michael Hillstrom, DNR Forest Health Specialist, Fitchburg
Michael.Hillstrom@wisconsin.gov
White, red and bur oaks have been experiencing increased mortality in Wisconsin and neighboring states over the last few years.
The causes of mortality are varied, but two-lined chestnut borer (TLCB) is the most common culprit. Wisconsin has switched from a period of historically wet years (2017-2020) to drought conditions that have become more severe each year (2021-2023). Add in frost damage, storm damage, increased growing season length and aging forests and the environmental recipe exists for stressed oaks that are more susceptible to attack by insects and diseases.
