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

With 145 invasive plants regulated under Wisconsin’s Invasive Species Rule NR40, it can be challenging to identify some of these plants while out in the woods.

The task can be further complicated by the presence of native lookalikes, plants that appear very similar to harmful invasive species but benefit wildlife, pollinators and ecosystems in Wisconsin.

Continue reading “Invasives And Imposters: Native Lookalikes To Know (Part 1)” →

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

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” →

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

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” →

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

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” →