Invasive plants disrupt ecosystems and rapidly reduce biodiversity. This episode takes a look at garlic mustard in North America and highlights some effective management strategies.

Title page for Biodiversity Killers Episode 2: Garlic Mustard

Quick jump to sections:

What’s the difference between native, non-native and invasive plants?
How to identify garlic mustard
What are the recommended management strategies?
How to properly dispose of garlic mustard

Welcome to the second in a series about biodiversity killers - plants that spread rapidly and take over ecosystems if left unchecked. Here, we take a look at some of the worst offenders and the best practices for managing them.

Missed the first one? Episode One on European buckthorn can be read here.

Before we dive into garlic mustard details, let’s get a better understanding of the differences between native, non-native and invasive plants.

Written description of native plants, photo of a bee flying towards purple flowers.

Chart of native plants and their characteristics

Description of non-native plants and a photo of pink peonies

Chart of non-native plants and their characteristics

Description of invasive plants and a photo of red berries of Japanese barberry

Chart of invasive plants and their characteristics

Invasive plants, like garlic mustard, share the following traits that allow them to thrive in new environments:

Chart of reasons why invasive plants spread successfully

When garlic mustard spreads unchecked, it forms dense patches that block sunlight from reaching the forest floor. This crowds out spring ephemerals like trilliums and bloodroot, which are critical early season food sources for native bees and other insects. It also prevents tree seedlings from establishing, reducing forest regeneration and overall biodiversity.

Two images of plant leaves, illustrating the difference between the leaves of first and second year plants

Photos of leaves, flowers, roots and seeds

Garlic mustard has been widely studied and several effective management strategies have been identified. This episode focuses on three key methods: hand-pulling, mowing and over-planting, each suited to different plant stages, seasons and population sizes.

One important detail to note: avoid mowing once plants have produced seeds. Mowing at this time will spread seeds and make the infestation worse.