Garlic mustard, brought to America as a herb, now invades 37 US states

Garlic mustard, introduced to North America by European immigrants in the 1860s as a culinary and medicinal herb, has become a woodland invader across 37 US states and six Canadian provinces. First reported on Long Island, New York, in 1868, it competes with native plants for resources, disrupts plant-soil relationships and thrives in shaded forests, making it hard to control.