Invasive Species


Help the City Tackle Garlic Mustard 

View of Garlic Mustard plantGarlic mustard is quickly becoming one of the area’s worst weeds. It is an upright biennial herb (blooms the second year of growth) that grows up to four feet tall in early spring and produces small, white flowers clustered at the top of each stalk. A native to Europe, it was originally introduced in North America by settlers for medicinal purposes and to use for cooking. Unfortunately, it has few natural enemies and each plant can produce thousands of seeds which may spread rapidly through wind, animals, clothing, and shoes. It then grows so quickly, it impedes native vegetation, creating what can be a permanent change in the habitat, much to the detriment of other plants and animals.

Proper removal and disposal is vital to reducing the spread of garlic mustard. It can be uprooted easily; however, garlic mustard should only be removed in early spring before the seed pods develop. Once removed, all parts of the plant should be placed in a garbage bag and disposed of in a garbage receptacle. Putting plants in compost or yard waste pickup will not prevent the seeds from sprouting and spreading. For large infestations, spray an appropriate herbicide or mow the area prior to flowering.

To help preserve the local and natural habitats from a garlic mustard invasion, the Portage Environmental Board sponsors garlic mustard pulls in several of the city parks each spring. Volunteers learn how to identify garlic mustard, remove it, and properly dispose of it. Please join the Board and other fellow citizens and businesses this year by volunteering to help pull garlic mustard at the following locations: 

2022 Garlic Mustard Volunteer Pulls - 9 AM to 12 PM 

  May 1     Ramona Park (8600 South Sprinkle) - Sponsored by the City of Portage Parks & Recreation

  May 7      Lexington Green Park  (4750 Pittsford)        Garlic Mustard (bloom closeup)

  May 15    South Westnedge Park (9010 South Westnedge)

  May 21    Portage Creek Bicentennial Park  (910 East Milham)    

No sign up necessary. (If you are planning a large group or corporate outing, please call 329-4422 to coordinate.) Gloves are provided but bring your own if you wish. Dress comfortably and be prepared to get a little dirty. You may want to bring a refillable water bottle.

Pulls will only be cancelled during severe weather.  To get updates on weather cancellations, additional volunteer opportunities, and upcoming board meetings, sign up for the Environmental Board Notify Me subscription on the City's main webpage.  Any questions may be directed to the Department of Transportation & Utilities at 329-4422. 


Spongy Moth (formally known as Gypsy Moth)

Spongy moths are a common pest species that feeds on the leaves of many trees common to Southwest Michigan, such as oaks, aspens, and willow trees. Most healthy trees can survive even complete defoliation for a few years. Spongy moth infestations can be unsightly and worrisome to homeowners who are concerned for the health of their trees.  These pests can be controlled through early identification and intervention, but in the worst case, these infestations are cyclical and will pass on their own after a few years.  The presence of an infestation can be reported at  For further information, the Michigan State University Department of Forestry has several publicly available resources for further research and consideration.  Read on... to learn more about Spongy Moths.