This shrublike, semi-woody perennial has bamboo-like stems that reach up to 10 feet in height.
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There are several approaches to treating Japanese knotweed.
Plus, it often requires multiple rounds of treatments to kill Japanese knotweed permanently.
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Here’s how to get rid of Japanese knotweed from your garden.
Identifying Japanese Knotweed
Japanese knotweed is a member of the buckwheat family.
The ecological impact of Japanese knotweed is severe everywhere.
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It has no natural pests or predators that keep it in check.
It chokes out native vegetation and reduces biodiversity, altering natural ecosystems and negatively impacting wildlife habitats.
Severe infestations will require repeated attacks throughout the year.
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Then, in late autumn and/or early spring, dig up as many of the rhizomes as you might.
Place the tarps back on for winter, so they’re already set for the next growing season.
Killing Japanese knotweed permanently might require several seasons.
The key is to stick with your project.
This weed can be completely eradicated with a dedicated effort on your part.
Find and compare quotes from top-rated professionals near you.
Bag all the debris to prevent it from taking root.
The stems have sharp edges that easily puncture plastic sheeting or tarps.
Cover the Area
Cover the plant area completely with thick-grade black sheet plastic or heavy non-canvas tarps.
If you must overlap pieces, see to it to overlap them by at least 2 feet.
The plastic should extend 5 to 10 feet outside the boundary area of the knotweed growth.
Trample Any New Shoots
As new shoots emerge over time, they might push up the tarps.
To crush them, trample over them walking over the tarps.
What growth does occur under the tarps won’t amount to much because it lacks sunlight.
Monitor and Repeat
Inspect the area weekly, and clip off any new shoots that appear.
This is an essential step, as cutting tends to stimulate Japanese knotweed into new growth.
It will likely require weekly cutting over many months to completely eradicate Japanese knotweed.
This is typically used concurrently with other methods.
Even the tiniest piece left behind is likely to sprout a new plant.
You’ll likely want to wear rubber gloves and protective clothing when using the herbicide to avoid skin contact.
Prune the Knotweed
Cut the Japanese knotweed to roughly 3 to 4 inches above the ground.
This will stimulate tender new growth that will readily absorb the herbicide.
Glyphosate works when it is absorbed by foliage to inhibit plant enzymes necessary for growth.
Foliage that turns yellow and dies indicates that the plant is dyingroots and all.
This herbicide method generally will kill Japanese knotweed permanently over time.
However, these methods are not effective.
You’ll have the same issue when attempting to kill Japanese knotweed with bleach or lime.
They often have more substantial tools and products that get the job done.
Japanese knotweed removal costs vary widely, depending on how widespread and stubborn your plants are.
A lawn service should be able to give you a quote for your specific area.
The good news is reputable lawn services often have a money-back guarantee that they can patch up the problem.
Glyphosate is recommended as the herbicide of choice for controlling Japanese knotweed.
otherwise, it will regrow.
There really isn’t a good natural remedy for Japanese knotweed.
Invasive Plant Profile: Japanese Knotweed.
University of Minnesota Extension.
Ann Occup Environ Med., vol.
32, 2020. doi:10.35371/aoem.2020.32.e28
Managing Japanese Knotweed.
Vegetation Management Department of Horticulture College of Agricultural Sciences, Penn State University.
Center for Invasive Species and Ecosystem Health.
Invasive Knotweeds Are Highly Tolerant to Salt Stress.
National Library of Medicine.
Vinegar: An Alternative to Glyphosate?University of Maryland Extension.
