Coltsfoot, (Tussilago farfara) above, is the first invasive to watch out for around Glen Lake. When you see our native Marsh Marigold (Caltha palustris) blooming, it’s time to scrutinize your property for coltsfoot. The bloom period of these two plants typically coincides.


The Glen Lake Association needs help finding this invasive springtime plant.

Spot Coltsfoot by looking for yellow flowers, seen below, 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. 

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 US Northeast, Midwest and Pacific Northwest as well as in southern Canadian farmland.

Throughout the coming season GLA will offer timely tips on various invasive plants to watch for on your property. When you are away or are unable to personally survey your property, perhaps a neighbor or friend could help out in your absence. Informed gardeners or property managers could also perform surveys. 

Marsh Marigold typically blooms at the same time as Coltsfoot.

As a service of the GLA, your shoreline will be surveyed for Coltsfoot if it is in the region known or suspected to be infested around Big Glen. However, we welcome your assistance in surveying any property around both Big and Little Glen Lakes. The more eyes, the better!

If you spot Coltsfoot, contact Laurel Voran at
231-632-3211 or Tricia Denton at

For more information see this site.