Garlic mustard is an invasive, nonnative plant that can take over a forest floor, crowding out native plants, including wildflowers. In the late 1800s, garlic mustard was brought to the United States from Europe for use as a culinary herb. Since then, it has spread across most states, including Missouri.
Garlic mustard can be distinguished from ;other woodland mustard plants by its characteristic odor of garlic from all parts of the plant and by the 2- to 4-foot-tall stalks covered with numerous small, four-petalled, white flowers in May.
Effects on Natural Communities
Garlic mustard occurs most frequently in upland and floodplain forests, savannas, and along roadsides. It invades shaded areas, especially disturbed sites, and open woodlands. It is capable of growing in dense shade and occasionally in full sun. Garlic mustard seeds seem to be spread by animals, by flowing water and by human activities. Because each plant disperses a large number of seeds, garlic mustard can outcompete native vegetation for light, moisture, nutrients, soil, and space as it quickly colonizes the area.
Garlic mustard should be accurately identified before attempting any control measures. If identification of the species is in doubt, the plant's identity should be confirmed by a knowledgeable individual and/or by consulting other appropriate resources.
Pulling
For new infestations and small populations, hand pulling can be effective if done before seed dispersal. The plants generally can be pulled up very easily.
Cutting
Cut the plant a few inches above the ground just after the flower stalks have elongated, but before the flowers have opened. If the plants have budded, they should be bagged and deposited in a landfill. If not completely removed, they will regenerate from any remaining parts and continue to produce seed. Repeat each year until the seed bank is exhausted.
Applying Herbicides
A foliar spray of 2 percent glyphosate can be applied to individual plants in the fall or very early spring when most native plants are dormant. In low-quality areas when non-target vegetation is dormant, apply 2, 4-D or 2, 4-D plus Dicamba, which is selective for broadleaf plants.
Burning
Annual prescribed burns in spring or fall can help eliminate the plant.