Look Out for this Invasive Species

Japanese Knotweed Terrorizes Wisconsin Backyards

Japanese Knotweed in Wisconsin

Knotweed is an invasive species that has plagued Europe and recently colonized North America, specifically the Great Lakes region. The knotweed infestation is far more distressing than a typical weed. It grows rapidly and powerfully, known for breaking through concrete and the foundation of houses. A rise of panic has spread as homeowners realize how the weeds have caused property value to plummet. In Europe, disclosing the presence of knotweed is mandatory on all deeds of sale. Banks will refuse to mortgage a property if it's contaminated with the plant. Knotweed isn't just an intrusive eyesore --it's financially devastating. Over several years, a car-sized plot of knotweed requires thousands of dollars in treatment.

The Origins of Knotweed in the United States

How did knotweed make its way to the U.S.? The plant first arrived in Manhattan in the late 19th century, sent to James Hogg from his brother in Japan. Decades later, a group of friends decided to plant it in the Bronx. From there came the outbreak that has spread across the northern United States. The New York City Parks Department has spent almost a million just to kill thirty acres of knotweed since 2010.

How to Remove Japanese Knotweed in Wisconsin

It takes a lot more than pulling out the roots to kill knotweed. Native to Japan, its initial outbreak in Europe was caused by a single specimen of the plant. Even without seeds, the stem fragments were enough to initiate the breakout. New knotweed plants can grow from a piece of root smaller than a penny. These fragments are spread by construction related digging and flooding. Roads, walls, buildings- there's no structure knotweed can't penetrate. Stems can stretch over 50 feet away from the roots, making it even harder to destroy the plant fully and completely. Removing knotweed is even more difficult near sources of water where the invasive species thrives best. The high-flow streams of Wisconsin springtime create an easy way for knotweed to spread and colonize somewhere new, making it important to maintain and regularly check your property.

Killing knotweed is hard to do on your own. It requires regular applications of glyphosate herbicide, which may take multiple seasons. After that, the surrounding soil must be carefully hauled away to ensure the weeds don't come back.

Don't Let Knotweed Take Control – Experienced Wisconsin Landscaping Company

Since knotweed is still unknown to many Americans, landowners can be confused when they first see the plant. Soon enough, it's completely taken over their property. If you encounter knotweed, contact our experts immediately so we can keep your yard free of infestation. The longer you wait, the more expensive the problem.

Brennan Landscaping is a full service landscaping company based in Wauwatosa WI, serving both commercial and residential landscape customers. Our goal is to establish lifelong customer relationships while serving all their outdoor landscaping needs.

Brennan Landscaping’s experienced landscaping contractors specialize in landscape design, construction and maintenance. Our team of Milwaukee area landscapers integrates creative landscape designs using quality materials capable of withstanding Wisconsin’s climate. We work with great attention to detail and an emphasis on customer service throughout the entire process.


Contact Brennan Landscaping for a free estimate on lawn maintenance services for homes and businesses throughout greater Milwaukee. 

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