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Japanese Knotweed

Invasive Species in Michigan

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What is it?

Japanese Knotweed is on Michigan's Invasive Species watch list and is prohibited. It is a stemmed plant with large, broad leaves that have pointed tips. It is easily identified by its bamboo-like stalks that are usually green or red in color. Long clusters of little white flowers appear in the spring.

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Impacting Local Habitats

Japanese Knotweed chokes out native species by blocking out light, changing the nutrient cycles in the soil and also releases toxins into the soil to prevent other plants from germinating. It spreads very quickly and is even more difficult to completely remove once it has taken root in an area.

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Do NOT mow Japanese Knotweed because small fragments can spread and create new plants. The best way to remove and prevent spreading is with controlled herbicides OR by pulling out the entire plant and its roots, black bagging them (be sure to tie the bag up tight!) and throwing them away. Do NOT compost Japanese Knotweed or relocate it.