Mustard plants

There are two members of the mustard family currently in bloom in Frederick County: the wild mustard (Synapis arvensis) and the garlic mustard (Alliaria petiolata). The difference between these plants is that wild mustard is found growing in open fields and has a yellow bloom, while garlic mustard is usually found growing in and around forests and has a white flower. Both of these mustard plants are native to Europe and Western Asia and were brought to this country in the 1800s as a potential food source.Garlic mustard usually grows in and around forests. (Courtesy photo)

Garlic mustard grows best in shady conditions and does not tolerate acid soils. This plant has become a major threat to herbaceous plant life in our more productive lower sloped and bottomland forests. Garlic mustard is a biennial plant that produces large amounts of seed that can stay viable in the soil 5 years or more. This plant grows quickly in the spring and can outcompete many native herbaceous plants.

In addition to its aggressive growth, garlic mustard produces allopathic chemicals that can poison nearby plants and causes the demise of beneficial mycorrizal fungi; this degrades the soil, creating conditions favorable for this and other plants that can grow on poor sites. Garlic mustard is also distasteful to deer and other animals, so they target more tasty plants and leave this opportunistic plant alone.

With all of these weapons at its disposal, it’s easy to see how garlic mustard can overrun a forest once it becomes established. Garlic mustard can be controlled by pulling it out of the ground and also by cutting it. It is important to conduct these control practices before the plant goes to seed; any control program should be conducted for 3- 5 years so as to target seeds that might be lying dormant. It is best to pull garlic mustard when the soil is moist so all of the plant is removed because if roots are left behind, they can develop into a new plant.

Garlic mustard can also be controlled by herbicides, but a long term strategy is also necessary for control due to the viability of seeds.

Wild mustard is a nonnative annual plant that is usually found in disturbed agricultural fields.

Sometimes a field can be completely covered with this yellow flowering plant. The seed of the wild mustard can remain viable for up to 60 years. The wild mustard can be a pest of agriculture but it rarely overruns native meadows, old fields or forests.

Nature Note for 5/11/2014