Viable seeds are produced within days of initial flowering. The seeds are believed to be dispersed on the fur of mammals such as deer, horses, and squirrels, by flowing water, and by human activities. Description Garlic mustard is a cool-season biennial herb that ranges from 12 to 48 inches in height as an adult flowering plant. Second-year plants generally produce one or two flowering stems with numerous small white flowers that have four separate petals. Stem leaves are alternate and triangular in shape, have large teeth, and can be 2 to 3 inches across in flowering plants.
Petioles are longer on the leaves toward the base.
Distribution and Habitat Garlic mustard is an exotic species introduced from Europe presumably by early settlers for its supposed medicinal properties and for use in cooking. It is widely distributed throughout the northeastern and Midwestern U.S. from Canada to South Carolina and west to Kansas, North Dakota, and as far as Colorado and Utah. In Wisconsin, the plant is currently concentrated in the southeastern and northeastern counties, although distribution records indicate its presence is nearly statewide. Garlic mustard grows in upland and flood plain forests, savannas, yards, barnyards, and along roadsides. It cannot tolerate acidic soils.