Threat of Invasive Plants

Invasive plant species are a threat to natural areas in Indiana. They displace native plants, eliminate food and cover for wildlife, and threaten rare plant and animal species. However, among natural resource professionals there is little consensus on which species constitute the greatest threat to natural areas. Consequently, species that are considered a grave threat by some resource professionals are still recommended by other resource professionals and sold by nurseries.

View videos about invasives in the Midwest’s natural areas:

Plants in the Wrong Places

Cultivating Awareness of Invasive Plants

Due to the threat invasive plants pose to natural areas around Indiana, INPAWS endorses the recommendations of the Invasive Plant Advisory Committee of the Indiana Invasive Species Council and asks this of the INPAWS membership:

1. Do not buy, sell, recommend, or plant species designated as invasive by the Invasive Plant Advisory Committee (listed here); and

2. Actively work to remove these species from landscapes around Indiana with permission of the landowner.


What’s an Invasive Plant?

The federal definition of invasive species is a non-native species  whose introduction causes or may cause economic or environmental harm or harm to human health.

Of the roughly 2,300 plant species growing outside cultivation in Indiana, approximately 25 percent are non-native. While most of these non-native plants cause little trouble, some of them are invasive and are responsible for degrading and destroying thousands of acres of natural plant communities in Indiana.  Control efforts for these invasive species are costing taxpayers hundreds of thousands of dollars each year.

Unfortunately, some of the worst invasive plants are still being sold by nurseries and planted by well-meaning Hoosiers, not realizing the problems they can cause. The good news is that there are non-invasive alternatives to these garden thugs. 

Why Should We Care?

  •  Invasive species cost the US over $138 billion per year.

  • Approximately 42% of threatened or endangered species are classified “at risk” due directly to non-native invasive species.

  • In the US, approximately 9% of forest products—worth a total of $7 billion per year—are lost as a result of non-native plant pathogens.

  • To date, about 5,000 types of alien plants are found in US ecosystems.

  • Alien weeds invade 1,730,000 acres of wildlife habitat per year in the US.

  • There are 180 non-indigenous aquatic species in the Great Lakes ecosystem. Of these, 15% cause serious harm.  (ISCC Facts)

Landscaping without Invasive Plants

We recommend three brochures for anyone who wants to plant an invasive-free landscape:

  • Invasive Plants in Indiana: Pretty…Awful!
    Highlights the biggest thugs and lists others that pose a threat, with suggestions of what to do in your own landscape.  View the brochure
  • Landscape Alternatives for Invasive Plants of the Midwest
    Prepared by the Midwest Invasive Plant Network. For every ornamental invasive plant commonly sold by nurseries, three or more noninvasive plants are suggested to enhance your landscape.  View the brochure  A free phone app is also available from MIPN.

For large orders of any brochure,  please pre-order at cost.  Call The Nature Conservancy at 317-951-8818 or email Ellen Jacquart.