Invasive Species

Help the City Tackle Garlic Mustard View of Garlic Mustard plant

Garlic 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.

Garlic Mustard (bloom closeup)

To help preserve the local and natural habitats from a garlic mustard invasion, the City of Portage Environmental Board encourages fellow citizens and businesses to help pull garlic mustard.

To receive alerts for upcoming board meetings and volunteer opportunities, 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.