Take on Invasives: Garlic Mustard

This is the second in a monthly series on invasive plant species in Northern Michigan, their impact on natural landscapes and what can be done to help control and prevent their spread.

Picture a carpet of vegetation so dense that your legs become lost in a sea of green as you wade through the forest. The woodland wildflowers that used to bloom here — Dutchman’s breeches, lady slipper, trout lily, trillium — have given way to a flood of invasive plants. Gone too are the diverse insects that once clamored over every blossom and propagated those beloved native flowers. What’s left are trees and an understory of nothing but garlic mustard.

A dense patch of garlic mustard.

“I used to have nightmares about it, where it just never ended,” said Heather Huffstutler, Land Protection Director for Huron Pines. “When it gets to knee high, it’s literally all you can see.”

It’s not just native blossoms and bugs that are impacted by garlic mustard. Woods that are near wetlands can lose important forage plants for animals like wood, box and Blanding’s turtles.

“If you have a bad enough garlic mustard infestation it outcompetes mayapple and you end up with a habitat that’s no longer suitable for turtles,” Huffstutler said of the wide-ranging consequences of this invasive plant.

Native to Europe and Asia, garlic mustard is a biannual that spends its first year storing up energy for swift growth in early spring of its second year. Outgrowing and shading other native plants, garlic mustard quickly fills in the understory, blooms and goes to seed. It’s dispersed easily across landscapes when its seeds become lodged in the feet of wildlife and the boots of human hikers, and those seeds can remain viable in the soil for many years.

Treatment is labor intensive. Plants need to be pulled by hand and bagged so that seed pods can’t ripen and open. An area with a heavy infestation will need to be treated for several years consecutively in order to deplete the seed bank in the soil. As the infestation recedes, reintroducing native plants by installing wildflower plugs can help restore the landscape.

Huron Pines AmeriCorps member Molly Fava pulls a handful of garlic mustard.

You can help avoid spreading garlic mustard by staying on marked hiking trails and using a hand-held boot brush to clean soil from your boots after each hike. Wherever you see a boot-brush station, use it. Suspected garlic mustard infestations can be reported to the Midwest Invasive Species Information Network (MISIN) at misin.msu.edu.

The Huron Heartland Invasive Species Network is made up of conservation groups, landowners, state and federal agencies that seek to restore native habitat through invasive species education, prevention and management. The Huron Heartland ISN is led by Huron Pines with support from the Michigan Invasive Species Grant Program (Michigan.gov/Invasives).

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