Garlic Mustard Identification and Management in the Landscape

Garlic Mustard Identification and Management in the Landscape

Garlic Mustard is actively growing and getting tall currently with the warmer temperatures. This weed is very aggressive and will take over any open spots in the landscape. Garlic Mustard, Alliaria petiolata, an invasive weed found throughout much of the east coast of the United States. Garlic mustard was first introduced from Northeastern Europe in the 1860s in Long Island, New York. Immigrants from Europe used it for food (an herb), medicine, and erosion control. It can be spread by water, insects, wind, animals, or humans. According to the U.S. Forest Service, “Garlic mustard poses a severe threat to native plants and animals in forest communities. Once introduced to an area, garlic mustard out-competes native plants by aggressively monopolizing light, moisture, nutrients, soil, and space.” The plant has no natural enemies.

This weed is a cool season biennial that produces a heart shaped coarsely toothed leaf which will appear on a stalked stem that will grow to 3.5 feet tall. The leaves will give off a garlic odor when crushed. During the winter the plant will have a green rosette that will remain very close to the ground, yet will be growing when temperatures are above freezing. Flowers will be produced with four petals that form a cross.

Each plant, according to research, (Kleinstein, 2001), can produce up to 15,000 seeds that are viable for up to 5 years, (Other references mention 3,000 to 8,000 seeds) that can be dispersed several feet from the plant. This is an invasive weed that likes shaded understory conditions, slightly acidic soils, and soils that are moist. This is a self-pollinating plant in many cases, and will shade out other plant species quickly. Removal by pulling will only be successful if the complete root system is pulled. As a cool season herb, garlic mustard will grow when temperatures exceed freezing. An opportunity to gain some control of this weed can be gained when selective treatment of garlic mustard is done while other plants are dormant, other plants have not yet appeared (spring) or have died for the year (late fall).

This article appears in May 2024, Volume 15, Issue 2 of the Agronomy News.

Agronomy News, May 2024, Vol. 15, Issue 2

Agronomy News is a statewide newsletter for farmers, consultants, researchers, and educators interested in grain and row crop forage production systems. This newsletter is published once a month during the growing season and will include topics pertinent to agronomic crop production. Subscribers will receive an email with the latest edition.

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