Invasive Plant of the Week: Narrowleaf Bittercress

The first-year rosette of narrowleaf bittercress. Photo: Wikimedia Commons.

By Joseph Mooney

Invasive of the Week: narrowleaf bittercress, Cardamine impatiens.

We’ve all heard of—and probably pulled tons of—garlic mustard and dame’s rocket, those ultra-invasive members of the mustard family. There’s another invasive mustard-family plant to look out for: narrowleaf bittercress (Cardamine impatiens), a European native introduced here as an edible green and medicinal plant.

This biennial is found in moist, shady, wooded areas, where it can form dense colonies that compete with native plants. Between May and September the seeds develop into approximately inch-long seed-filled structures called siliques that separate when mature. A spring-like mechanism in the silique ejects the seeds out a great distance from the plant. A single plant may contain as many as 5,500 seeds, according to the Minnesota Department of Agriculture.

The seed pods of narrowleaf bittercress. Photo: G. Mittelhauser, Native Plant Trust.

Besides C. impatiens’ neat mechanical adaptation for self-sowing, its seeds can spread by moving water or by latching on to clothes, animals, even the tires of bikes or cars. Hand-pulling young plants before they set seed is the preferred way to eradicate bittercress, making sure to get the roots. Pulled plant material can then be composted.

The leaves and young shoots are edible raw or cooked. When moving any mature bittercress plant material be careful not to spread the seeds to other locations.

For native alternatives to narrowleaf bittercress try planting wild stonecrop, heartleaf foamflower, wild geranium, woodland phlox, eastern red columbine, wild ginger, or wild strawberry.