Invasive Species

Explore why invasive plants are a concern in the St. Louis region and learn what you can do to help address them. 

Invasive Plants 101

Why Should You Care?

Ecology and Environmental Impacts

Invasive plants pose a major threat to biodiversity. It is estimated that 40% of species listed as endangered or threated in the United States have become imperiled due to invasive species alone or their combined impact with other destructive forces.

Invasive plants spread aggressively and cause major environmental changes such as the decline or complete elimination of native plant populations, which in turn impacts the insects and pollinators that depend upon native plants.

Some invasive plants can completely change the natural habitat they invade, such as the conversion of native grasslands or woodlands into dense shrub thickets.

Other invasive plants cause damage in more subtle ways. They alter the composition of the soil or change water chemistry in our streams, making it difficult for other plants, insects, and microbes to live there. They can also change the natural fire cycle of native ecosystems or increase soil erosion.

Even more subtly, some invasive plants can hybridize with native plants. Over time, this can completely wipe out the native plant. For instance, in the Saint Louis region, invasive oriental bittersweet can hybridize with the native American bittersweet.

What Can You Do To Help?

Learn to identify invasive plant species in our region (see Species List below) and how to distinguish them from any native species that are similar in appearance.

Avoid using invasive plants in your garden. Until you are able to get rid of invasive plants in your yard, be responsible and remember to remove and destroy seeds of invasive plants to prevent their dispersal into natural areas. Don’t share invasives with other gardeners.  Ask your local nursery not to sell invasive plants and to provide native alternatives.

Don’t plant invasive plants for wildlife. Native species provide much better food and cover for native wildlife.

Volunteer to help remove invasive species in local parks and natural areas.

Pass it on! Tell your friends and family about the threat from invasive species.

Invasive Species in the St. Louis Region