Are You in Violation of NR40?

        I would bet that 95% of property owners reading this have one or more plant species on their property that violates NR40, the Wisconsin DNR’s invasive species rule.

        Some of you know that you do.  Perhaps you’ve got a woodland where invasive buckthorn or garlic mustard is past any chance of control.  Or maybe you have a lilac or forsythia in your backyard with a few stalks of buckthorn entangled among the stems and it’s just been too much trouble to try to get in there and cut the buckthorn out.

        Others of you don’t know that you are harboring invasives.  Even those living in the middle of a city with nice, tidy landscapes may be growing some of the bad guys.

        If you’ve been reading this “Plant Matters” column in Badger Sportsman magazine for any length of time, you’ve seen almost constant references to NR40 in the columns about invasive species.  NR40 lists 131 plant species, 70 animal, insect and fish species, and 8 fungus and bacteria species that are either Restricted or Prohibited in our state. 

        When a species is classified Restricted, it is illegal to buy, sell, transport, or release the species into water or on land.  Prohibited species have the added condition that you may not possess them.  While you are required by NR40 to eradicate – or ask the DNR for help in eradicating – Prohibited species from your property, you are not required to remove Restricted species, although you are strongly advised to do so. 

        Let’s take a look at some of the surprising plants on NR40’s list of invaders.  Which of these are you growing?

Amur Cork Tree

Amur Maple

Bishop’s Goutweed

Black Locust


Burning Bush

Canada Thistle

Common or Glossy Buckthorn

Creeping Bellflower

Dame’s Rocket

Garden Heliotrope


Japanese Barberry


Oriental Bittersweet

Parrot Feather

Porcelain Berry

Queen of the Meadow

Ribbon Grass

Russian Olive

Siberian Peashrub



Tree of Heaven

Water Hyacinth

Water Lettuce

White Mulberry

White Poplar

Woodland Forget-Me-Not

Yellow Iris

        For a complete list of plants both Prohibited and Restricted by NR40, see and click on “Species List.”  Each species has a fact sheet that you can click on to learn more about the plant and how to control it.  Some control methods are as easy as dig it up and compost or trash it, while others require more effort.

        Don’t panic if you see something on the list that is in your landscape.  At least, don’t panic immediately – you aren’t going to jail for it.  First, check to be certain that the plant in your yard is actually the one on the list.  You can do this by looking at the photos on the DNR website to match it up with what you have growing.  Also, take a look at the Latin name of the plant listed to be sure that what you are calling the plant and the common name of the plant listed in NR40 are in agreement. 

        Why would you care about Latin names you ask?  Many plants have different common names in various parts of the country.  And sometimes different plants have the same common name.  But each plant has one and only one Latin name.  For example, one of NR40’s Restricted plants is burning bush, Euonymus alatus.   It is a woody plant very often used as a foundation plant or specimen plant.  In fall the foliage turns a brilliant and beautiful bright red.  Then there is another plant called burning bush that grows in a shrub-like shape and has bright red foliage in fall, but it is an annual plant, dying at the end of the growing season.  This burning bush has the Latin name Kochia trichophylla and is not listed in NR40.

        Complicating matters further, the listed plant, Euonymus alatus has other common names besides burning bush, including burning tree, winged burning bush, burning euonymus, winged wahoo and winged spindle-tree.  See the problem? 


Invasive plants are non-native species or strains that establish in natural plant communities and wild areas and replace native vegetation.


Wisconsin Statute 23.22:  Nonnative species whose introduction causes or is likely to cause economic or environmental harm or harm to human health.


  • Rapid, effective reproduction and spread by seed or vegetatively
  • High growth rate / productivity
  • Variable and adaptable – able to thrive in a wide range of environments
  • Ability to out-compete, stress and kill native species – early leaf out, frost resistance, secrete toxins into the soil
  • Lack of natural predators – disease or insect

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