Invasive Plants Don't Have To Be Scary!

When you take a trip out to Cowles Bog, the first ecosystem that greets you is the wetlands. The signature water-loving plants and birds offer welcoming waves and sing the tunes of the dunes. But looming in the distance is an invasive tall grass more frightening than any halloween ghoul: phragmites! 

Phragmite grass

Invasive species are non-native species that cause harm to the health of the environment, animals, or plants in the area. Phragmites are very aggressive thanks to its seed production and rhizome network. Phragmites spread from ecosystem to ecosystem quickly because they produce up to 2,000 seeds a year! Their rhizomes, an extensive network of underground stems, are also used to create new plants. Rhizomes can grow 1 to 3 feet below soil surface and can creep horizontally up to 10 feet in a season! To make things worse, phragmites can grow up to 15 feet tall and out-compete plants below them for valuable sunlight. All of these factors make it extremely difficult for plants to cohabitate with phragmites. 

For a National Park that is well-known for its plant and animal biodiversity (ranking fourth most biodiverse out of all National Parks), plants like phragmites threaten this biodiversity with their quick reproduction and ability to survive difficult conditions. 

But don't be scared, we don’t have to let phragmites haunt our wetlands! There are different techniques to help bring native ecosystems back from the grave, reviving them to their natural state. Several sites in the National Park were once overgrown with phragmites, but thanks to consistent hard-work of phragmite phighters the native plants are thriving in recovered wetland ecosystems. 

Before and after phragmites removal at west beach

There’s something you can do to help protect your park, too. Using a stiff brush or a boot cleaning station before and after the next time you hit the trails you keep seeds from accidentally planting themselves in the ecosystems you’re visiting. Also, just by visiting your outdoor spaces you’re proving why we should invest into protecting our ecosystems from being overtaken with invasive plants. With your help we can keep our natural gems free from invasives for generations to come! 

NOTE: There are both native and invasive phragmite in the Dunes. Native phragmites have a purple-red hue to the stem and have leaves with a yellow tint, while invasive phragmites have a dull green stem with bluer leaves. 

Lily Olander

Environmental Education Fellow