This invasive species competes with native plants, such as wild flowers and tree seedlings, for light and space. Garlic mustard (Alliaria petiolata) is usually able to out-compete the natives, and spreads rapidly. It is also a bad species for butterflies, since the butterflies lay their eggs on the plants but the larvae cannot survive due to the different chemistry of the garlic mustard leaves.
This invasive species gets its name from the odor emitted by its crushed leaves. Rosette leaves, which are kidney-shaped, are formed early in the spring. Second year plants bolt, sending up flowering stalks with clusters of small white flowers.
Plants can easily be pulled when the soil is damp, or can be cut at ground level in the spring, or sprayed with Glyphosate.
There are similar native plants that are much better for the environment, such as the basal leaves of Thaspium, Zizia, Senecio, and Viola species.