Herbaceous biennial with stems 2-4’ tall. First-year plants form a basal rosette that remains green through the winter. Second-year plants produce one to several flowering stems.
- Invades high quality upland and floodplain forests and savannas, as well as disturbed areas, such as yards and roadsides. It is sometimes found in full sun, though most often grows in areas with some shade, and does not do well in acidic soils.
- Native herbaceous cover has been shown to decline at sites invaded by garlic mustard.
- Garlic mustard exudes antifungal chemicals into the soil that disrupt associations between mycorrhizal fungi and native plants, suppressing native plant growth.