Invasive plant

Avoid Hitchhikers This Summer

By Erika Segerson-Mueller, DNR invasive plant program specialist, Oshkosh
Erika.SegersonMueller@wisconsin.gov or 715-492-0391

Invasive jumping worms have a light-colored clitellum, while most worm species have a raised, pink clitellum. / Photo Credit: Brad Herrick, UW-Madison Arboretum

To reiterate some advice you may have heard long ago from your parents: Don’t give rides to hitchhikers. They may have been thinking about people, but hitchhiking invasive plants, insects and pathogens are also worthy of concern.

As you dream of days spent at the cabin up north, planting your garden or wandering in the woods, here are a few reminders to help you avoid bringing hitchhiking invasives along as you enjoy your spring and summer activities. Continue reading “Avoid Hitchhikers This Summer”

The Scourge Of Spurge, Both Cypress And Leafy

By Erika Segerson-Mueller, DNR invasive plant program specialist, Oshkosh;
Erika.SegersonMueller@wisconsin.gov or 715-492-0391

Photo showing the white milky sap of spurge plants, sometimes called “wolf’s milk.”

The white milky sap of spurge plants, sometimes called “wolf’s milk,” can be toxic to cattle and irritating to human skin. / Photo Credit: Norman E. Rees, USDA Agricultural Research Service Retired, Bugwood.org

Managing invasive plant species can really be a pain. When the plants you are targeting can potentially harm human health, that pain can become quite literal.

Leafy spurge (Euphorbia esula) and Cypress spurge (Euphorbia cyparissias) are restricted invasive plants under Wisconsin’s Invasive Species Rule NR40. Aside from their tendency to spread aggressively and displace native species, both plants contain a white milky sap that can cause skin irritation in some humans and is potentially toxic to cattle and horses. Continue reading “The Scourge Of Spurge, Both Cypress And Leafy”

On The Outs With Goutweed

By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh Service Center;
Erika.SegersonMueller@wisconsin.gov or 715-492-0391

Photo of Bishop’s goutweed, a common garden ornamental that may be better known to home gardeners as “snow-on-the-mountain.”

A common garden ornamental, Bishop’s goutweed may be better known to home gardeners as “snow-on-the-mountain.” / Photo Credit: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Introduced as an ornamental plant commonly planted in gardens, Bishop’s goutweed is a restricted invasive plant in Wisconsin under Invasive Species Rule NR40.

Also known by common names such as snow-on-the-mountain, bishop’s weed and goutwort, the variegated variety with white edges will probably look familiar to many gardening enthusiasts. Continue reading “On The Outs With Goutweed”

Dropping The Aphid Grenade On Garlic Mustard

By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh Service Center;
Erika.SegersonMueller@wisconsin.gov or 715-492-0391

Photo showing that leaves appear wrinkled and less healthy in garlic mustard plants affected by aphids.

Leaves appear wrinkled and less healthy in garlic mustard plants affected by aphids. / Photo Credit: Rebecah Troutman, Holden Forests and Gardens, Bugwood.org

The NR40-restricted invasive plant garlic mustard (Alliaria petiolata) is prevalent in many Wisconsin woodlands, but a new wave of hope is on the horizon.

The garlic mustard aphid, a tiny, dark, gray-to-green insect sometimes called the “grenade” aphid after the pattern of raised blotches on its back, was found in 2021 at the Holden Arboretum in Ohio. It could become a viable form of biocontrol for the garlic mustard plant.

Continue reading “Dropping The Aphid Grenade On Garlic Mustard”

Weed Management Area Grant Deadline Nears

By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh Service Center;
Erika.SegersonMueller@wisconsin.gov or 715-492-0391

Controlling invasive plants on your forested property can be a challenging and costly endeavor. The Weed Management Area – Private Forest Grant Program (WMA-PFGP) helps make this process easier for its recipients. Though the April 1 application deadline is quickly approaching, there is still time to apply for funding for your forest.

Continue reading “Weed Management Area Grant Deadline Nears”

Forget About Planting Forget-me-nots

By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh Service Center;
Erika.SegersonMueller@wisconsin.gov or 715-492-0391

Wide-angle photo of a forest road covered by a blanket of Woodland forget-me-not.

A forest road is covered by a blanket of Woodland forget-me-not. / Photo Credit: Caleb Slemmons, National Ecological Observatory Network, Bugwood.org

These easy-to-grow, sweet-sounding, small blue flowers may seem appealing, but you should forget about forget-me-nots. A garden plant frequently found in mixed bouquets, forget-me-nots can easily escape the confines of a garden and spread aggressively.

There are two species regulated as invasives in Wisconsin: an Aquatic forget-me-not (Myosotis scorpiodes) and Woodland forget-me-not (Myosotis sylvatica). Both species are restricted under Wisconsin’s Invasive Species Rule NR40, so control is encouraged if they are found on your property. These species cannot be transferred, transported or introduced without a permit.

Both the aquatic and woodland species of forget-me-not bloom in early spring and can share many visual characteristics. Continue reading “Forget About Planting Forget-me-nots”

‘In The Weeds’ With Invasives Tech

By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh;
Erika.SegersonMueller@wisconsin.gov or 715-492-0391

Photo of popular garden plants including tulips and daffodils.

While not native to the Midwest, popular garden plants such as tulips and daffodils do not spread outside of gardens or cause harm, therefore they are not invasive. / Photo Credit: Lesley Ingram, Bugwood.org

As the conversation around invasive plants grows, it’s easy to get “stuck in the weeds” when it comes to invasive terminology.

A simple Google search of “invasive plant” will produce a variety of definitions, bringing in technicalities or muddying your understanding with each new idea of what invasive means. Continue reading “‘In The Weeds’ With Invasives Tech”

Invasive Species Find The Spotlight In February

By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh Service Center;
erika.segersonmueller@wisconsin.gov or 715-492-0391

Graphic showing home page for NISAW.org-slash-forest, titled Invasive Species Are Damaging Our Forests

One focus for policy development during NISAW 2024 is forest health and invasive plants. NAISMA has created an easy way to contact your elected officials to let them know you support the Invasive Species Prevention and Forest Restoration Act. / Image Credit: NAISMA.org

While February in Wisconsin may bring to mind snow-covered ground and little new plant growth, it’s quite a big month for action in the invasive species world. The last week of February brings National Invasive Species Awareness Week (NISAW), an international event that focuses on legislation, policies and funding for the prevention and management of invasive species.

Continue reading “Invasive Species Find The Spotlight In February”

Don’t Let Japanese Barberry ‘Tick’ You Off

By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh Service Center;
erika.segersonmueller@wisconsin.gov or 715-492-0391

Photo showing Japanese barberry quickly growing into a dense infestations in a forest.

Japanese barberry can quickly grow into dense infestations in forests, outcompeting native plants and providing ideal hiding places for white-footed mice that serve as hosts for blacklegged ticks. / Photo Credit: Wisconsin DNR

Most small talk in Wisconsin revolves around three things: the weather, the Green Bay Packers … and in the summer months, how darn bad the ticks are.

If you spend time working or playing outside, you likely know firsthand that ticks in Wisconsin are serious business. Because most of us prefer to minimize our interactions with the tiny arachnids, here’s another tick prevention tactic to add to your arsenal — along with clothing treated with permethrin, long socks and frequent tick checks: Rid your property of Japanese barberry.

Continue reading “Don’t Let Japanese Barberry ‘Tick’ You Off”

Just Say ‘No’ To Knotweeds

Photo showing a worker logging a large roadside infestation of knotweed.

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.

Continue reading “Just Say ‘No’ To Knotweeds”