Invasive Species Spotlight: Garlic Mustard (Alliaria Petiolata)
Garlic mustard is one of those invasive species that seems to fly under the radar as it encroaches on more and more land. It was introduced from Europe in the 1800’s as a food and medicinal plant.
As a biennial it produces low-growing, non-flowering rosettes the first year of its life and then really takes off by producing 12 – 36” plants the second year. It is during this second year that it really does the most damage because that is when it flowers and produces many slender pods that contain more than 5,750 seeds per square foot. What’s worse is that each of those seeds will either sprout into another plant or lay dormant in the soil for up to 10 years, growing whenever conditions are just right.
This relative of broccoli and cauliflower is most commonly found in the eastern part of Kansas be-cause it prefers the cool understory of forests. It will quickly form a dense understory by crowding out other species and producing chemicals that restrict the growth of competitive plants.
Control is difficult but as a biennial, pulling the plants will successfully kill them. For larger, well establish infestations, applications of glyphosate in the early spring or late fall while the plant is dormant should work. Remember, because of the long life of the seeds you will have to continue to control the plants until the seed bank is exhausted.