Invasive Coltsfoot: Be On the Lookout

by | Apr 25, 2024 | Invasive Species, News

We need your help! Unusually warm early-season temperatures mean now is the time to spot the blooms. Coltsfoot was first identified along the shores of Big Glen in 2008 and is believed to have hitchhiked here with other landscape material. Coltsfoot is comparable to bamboo in its resistance to eradication and by 2012 that single infestation had spread by seed and rhizome to other properties within a 4-mile zone.

Spot Coltsfoot by looking for yellow flowers, seen above, that emerge before the leaves and open on sunny days. The flowers are similar in appearance and size to a dandelion’s, but with the addition of leafy bracts along the stem. Later in the season, after the flowers have matured, Coltsfoot can be identified by thick, fleshy, heart-shaped leaves, up to eight inches long and wide, as shown in the photo below. 

Coltsfoot first invades sunny, low-lying wet areas, but is very adaptable and if left uncontrolled can spread into bright, high and dry zones quickly. It can also grow, bloom and spread in shade, though with less vigor. If left uncontrolled, Coltsfoot has the potential to completely blanket a sunny spot, decreasing biodiversity along with your property value. It threatens to invade the same habitat of our precious endangered species, the Michigan Monkey flower. If it escapes the shores of Glen Lake, Coltsfoot threatens our surrounding agricultural communities. It has proven to be an agricultural pest in the U.S. Northeast, Midwest and Pacific Northwest as well as in southern Canadian farmland.

With consistent effort and the cooperation of property owners in the affected areas over the past several years, we are now close to completely eradicating this aggressive plant. Please let us know if you see Coltsfoot on your property or in our watershed.