Terrestrial Invasive Species in St. Louis County
Terrestrial invasive species are non-native plants that pose a serious threat to native ecosystems. These aggressive invaders outcompete and displace native trees, shrubs, and wildflowers, often leading to a significant loss in biodiversity. Unlike native species, invasives do not provide the same ecological benefits, and as their presence increases across the landscape, native plant and animal populations decline. Many invasive species in northern St. Louis County are at the leading edge of their spread. This makes early detection and rapid response essential. Once widely prevalent, management of invasive species can be extremely costly and difficult.
Photo of an invasive Siberian Peaschrub (Caragana arborescens) plant
The North St. Louis Soil and Water Conservation District (SWCD) is actively involved in managing terrestrial invasive species in North St. Louis County through the Cooperative Weed Management Area (CWMA) grant. This program engages landowners in controlling priority invasive plants in natural areas.
High-Priority Invasive Species in St. Louis County
- European and glossy buckthorn (Rhamnus cathartica, Frangula alnus)
- Non-native honeysuckles (Lonicera spp.)
- Japanese and Bohemian knotweed (Fallopia japonica, Fallopia × bohemica)
- Japanese barberry (Berberis thunbergii)
- Wild parsnip (Pastinaca sativa)
- Garlic mustard (Alliaria petiolata)
- Purple loosestrife (Lythrum salicaria)
- Marsh thistle (Cirsium palustre)
- Leafy spurge (Euphorbia esula)
- Garden valerian (Valeriana officinalis)
- Queen Anne’s Lace (Daucus carota)
- Meadow knapweed (Centaurea jacea)
- Flowering Garlic Mustard (Alliaria petiolota)
- Siberian peashrub (Caragana arborescens)
If you notice any of these species in northern St. Louis County, (north of Cotton), please contact Corey Denning at corey@nslswcd.org or (218) 288-6143.
You can also report sightings using mobile apps like EDDMapS or WildSpotter. Financial assistance for invasive species management on your property may be available.