An invasive plant has been making its presence known in the Chicago area the last few years, but you will only see it in the early spring. Now is the best time to look out for Lesser Celandine (Ficaria verna), an aggressive spreading and mat-forming plant. It grows primarily in moist shady areas, although it will tolerate drier, sunny locations as well. It’s in our gardens, our alleys, our parkways, and unfortunately, spreading like wildfire in our natural areas. This week I am seeing entire front lawns, ravines and streambeds overrun with it on the North Shore.
It is easiest to identify by looking at the yellow flowers are 1-3” in diameter, yellow and usually 8-petaled on stalks. The leaves are heart or kidney-shaped, somewhat shiny, and on stalks also. They are sometimes mistaken for yellow violets or our native Marsh Marigold, which blooms at the same time in moist soils. Marsh Marigold has 5-6 petals.
The native Stylophorum diphyllum, commonly known as celandine poppy, is not related to lesser celandine.
Marsh Marigold Lesser Celandine
This plant poses a particular threat to our early spring ephemeral wildflowers, crowding them out by emerging just a little bit before they do and blocking the light. They reproduce vegetatively through underground tubers and also via bulblets at the base of the leaf stalks. They also reproduce through seed which is often dispersed by running water.
The roots are not too deep, and it is possible to dig them out if you have a small number of them, but be sure to remove the roots, tubers and bulblets, which tend to loosen themselves and fall to the ground while you are digging. After digging, be sure to clean your tools well, so you don’t move it to new locations on your tools.
Although we are always reluctant to use herbicides, if you have a large area that is infested with this plant, this may be the best way to help maintain a diverse population of native plants in the wooded understory. It is best to apply herbicide before lesser celandine has begun flowering, to avoid harming bees.
Due to the inherent health and environmental risks of using herbicides, if you think you require an herbicide application to control lesser celandine or another invasive plant, please contact us or another trained and certified herbicide professional.