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Garlic mustard pull at Cottage Grove Ravine Park

With 515 acres of hills and heavily wooded ravines, a small lake and a smattering of small prairies, Cottage Grove Ravine Regional Park features a beautifully diverse landscape. A glacial tunnel valley bisects the park, featuring 80- to 100-foot slopes which are home to a compelling array of vegetation and habitats. The ravine ends in a small lake where people enjoy fishing, birdwatching and picnics.


Cottage Grove Ravine Regional Park Cottage Grove , MN
United States
44° 48' 35.6472" N, 92° 54' 3.3516" W
Minnesota US

How to Stack, Pile, And Burn Brush

Flint Hills brush pile

Volunteers add to large piles of brush at the 2021 annual Flint Hills brush haul.

Giant piles of stacked buckthorn and brush from Cottage Gro

Invasive species: Garlic mustard

Garlic mustard

Garlic mustard is a delicious plant that can spread rapidly in woodlands, disturbed areas and along waterways in Minnesota. Look for it in early spring. (Photo by Rich Wahls for FMR)

 Learn more about garlic mustard and how you can help restore balance for wildlife and water quality by removing these plants before they flower.  >>

Help remove invasive species: spotted knapweed

Spotted knapweed

Spotted knapweed is a non-native, invasive plant. Photo by Lisa Foster

Brought over accidentally in ship ballast in the 1800s, this Eurasian plant's spread can threaten the diversity and balance of a prairie. It is phytotoxic, meaning it chemically alters the soil to poison neighboring plants. Because so few prairie areas remain in our state — less than 1% of what was historically present — spotted knapweed reduction is a top priority in any restoration project.

Invasive species: Why do they matter?

A young volunteer with garlic mustard

A young volunteer points to invasive garlic mustard, one of the invasive species that FMR volunteers spend hours each year removing.

Invasive species are a problem around the globe. Terms like native and non-native refer to the natural habitat range of a species. A non-native species is one that is present in an area outside of its natural range. Ecologically, this can have consequences for both the species and the receptive system. For example, as plants, insects and animals evolve together, they adapt to protect themselves from and compete against the other species in their habitat. Plants produce phytotoxins to protect themselves from being eaten, and insects and animals develop enzymes to break these toxins down.