Fells Invasives – Garlic mustard

National Invasive Species Awareness Week (NISAW) is February 26 to March 3, 2024.

To recognize NISAW, we will be releasing a blog post every day this week on a different invasive plant species commonly found throughout the Fells.

Invasive plants are non-native plants that were introduced to our area from another region of the world. The elements that kept the non-native plant populations in check in its home region (e.g. disease, competition, predators) are no longer present once they are introduced to this new region. This means that the plant can grow out of control, rapidly outcompete native plants, and threaten native biodiversity. This threat to our native habitats and biodiversity makes management of invasives all the more important.

Read on to learn more about today’s invasive plant: Garlic mustard.

John Fielding / “Jack-by-the-hedge” or Garlic Mustard / CC BY-SA 2.0

Garlic mustard (Alliaria petiolata)

A much smaller plant than the vines and shrubs we discussed so far, garlic mustard is a biennial herb, which means that it takes two years to mature and complete its life cycle. Garlic mustard is native to Europe and parts of Asia. It was brought over to the United States in the 1860s, likely for cooking and medicinal uses.

First year garlic mustard presents as a rosette with smaller, rounder leaves that remain close to the ground. Second year garlic mustard experiences a significant growth spurt, reaching up to three and a half feet in height. It produces small white flowers in April and May, which give way to long thin seed pods that appear in June packed with thousands of seeds. By the middle to late summer the plant dies.

Photo by Ryan Hodnett

Garlic mustard is aptly named. When crushed, the plant’s leaves smell like garlic. The plant can also be eaten if prepared correctly. Younger plants make for better eating as they are less bitter, and older plants contain cyanide, so they need to be cooked thoroughly before eating. It can be used in salads or to make a pesto.

While it was just used in the kitchen in the nineteenth century, it eventually spread to become a problem in forests and other habitats. Garlic mustard is allelopathic, which means it produces and releases chemicals into the soil that prevent the growth of other plants. This gives garlic mustard an obvious chemical advantage over its native neighbors.

Thank you for joining us this week to learn more about some of the invasive plants found in the Fells! Want to help us combat invasive plants like garlic mustard? Join us for a volunteer day by signing up on our calendar here!