WASHINGTON COUNTY, WI — Washington County participated in the Southeastern Wisconsin Invasive Species Consortium (SEWISC) Garlic Mustard Pull-A-Thon for the first time this year. Since 2013, SEWISC has brought together communities across the region to protect local woodlands from invasive species—especially garlic mustard.
Washington County’s Natural Resources Department joined partner organizations including Cedar Lakes Conservation Foundation, MMSD, Restoring Lands, and Riveredge Nature Center for the competition. The County hosted three volunteer pull events at Glacier Hills and Homestead Hollow County Parks, collecting 76 bags of garlic mustard and dame’s rocket.
By removing invasive plants that degrade natural ecosystems, volunteers help protect the land resources that support Washington County’s quality of life and strengthen the region’s appeal for residents, visitors, and businesses. For more information about garlic mustard or upcoming invasive-species volunteer opportunities, contact parks@washcowisco.gov.
About Garlic Mustard Garlic mustard (Alliaria petiolata) is an invasive, cool-season biennial herb that threatens Wisconsin’s forests and natural areas. Introduced from Europe, it spreads quickly in woodlands, floodplains, savannas, and even disturbed areas such as yards and roadsides. The plant outcompetes native wildflowers and tree seedlings by emerging early, forming dense stands, and releasing soil chemicals that disrupt the mycorrhizal fungi native plants rely on. First-year plants grow as low rosettes, while second-year plants produce tall flowering stems with white four-petaled blooms and long seedpods that can remain viable for years. Left unmanaged, garlic mustard reduces native plant diversity and degrades habitat for insects, birds, and wildlife that depend on healthy, diverse plant communities.1
