Invasive Species


Help the City Tackle Garlic Mustard 

View of Garlic Mustard plantGarlic mustard, an upright, herbaceous biennial that grows up to four feet tall, is the most destructive plant in Portage. The small white flowers have four petals clustered at the top of the stalk. Each plant can produce millions of seeds which spread rapidly in wooded areas by wind, animals, clothing and shoes. Its rapid growth impedes native plants and can stifle new forest growth. Proper removal and disposal is vital to reducing the growth of garlic mustard. 

Garlic mustard can be uprooted easily and should be disposed of in plastic garbage bags. Plants should not be pulled after the seed pods turn brown. Do not put plants in compost or lawn recycling pickup since the seeds will sprout and spread if not disposed of properly. Large infestations can be sprayed with an appropriate herbicide. It is also acceptable to mow large carpeted areas prior to flowering. 

Group Photo 5-5-18Pull 5-5-18

The Portage Environmental Board annually sponsors garlic mustard pulls in city parks, enlisting the help of Portage residents and businesses as volunteers. Volunteers learn how to identify garlic mustard, remove it and properly dispose of the invasive species. 

2020 Garlic Mustard Volunteer Pulls - 9 AM to 12 PM 

April 25 @ Ramona Park  - CANCELLED 

May 2 @ Lexington Green Park - CANCELLED

May 9 @ South Westnedge Park - CANCELLED

May 16 @ West Lake Nature Preserve - CANCELLED

May 30 @ Schrier Park (850 West Osterhout Avenue)

June 6 @ Bicentennial Park (910 East Milham Avenue) 

Pulls will be cancelled only for severe weather. Residents can sign up for the Environmental Board Notify Me subscription to get updates on weather cancellations, additional volunteer opportunities and upcoming board meetings. Please contact the Department of Transportation & Utilities at 329-4422 with any questions. 


Gypsy Moth

Gypsy 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. Gypsy 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 Gypsy Moths.