How To Get Rid Of Knotweed
Knotweed, also known as prostate weed or Polygunum avicular, is one of the most common invasive perennial weeds you'll find in lawns. It begins growing close to the ground and will gradually spread out across a larger area. Although Knotweed can start out small, it can completely overtake your lawn in a short period.
States like Florida are experiencing more and more cases of knotweed invasions. Much like other difficult weeds, knotweeds use both seeds and their spreading rhizomes to quickly creep across the ground. Knotweed is not picky with where it grows - fields, disturbed soil, roadsides, ditches, areas with high moisture, and even swamps and marshes.
Key Takeaways
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Knotweed is not only stubborn but is also one of the most aggressive weeds, with its large quantity of seeds and extremely quick growth.
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We recommend a potent, selective herbicide such as Quincept Selective Herbicide or Quali-Pro MSM Turf Dry Flowable Herbicide with Alligare 90 Non-Ionic Surfactant.
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In more severe cases, it may require a non-selective herbicide containing glyphosate.
Knotweed Identification And Inspection
Characteristics Of Knotweed
Before you begin the knotweed removal process, you'll need to be able to properly identify this invasive plant. You may begin to notice Knotweed in the early summer as it progresses and develops slowly, reaching full strength in early fall.
By the middle of summer, you'll be able to clearly spot the obvious signs of Knotweed invading your yard. Instead of growing vertically like the majority of weeds, Knotweed grows laterally across the affected area. This lateral spread quickly makes your property an eyesore if not dealt with in short order.
As you try to identify this weed, you may notice the plant is growing in mats, featuring thin, tall stems and thick nodes. Very small white or pink flowers grow along the stems. Easily mistaken for purslane, spotted spurge, and other weeds, Knotweed does have some key differences in appearance and how its leaves are arranged.
A few of the key components of this weed you'll want to look for are its long, narrow leaves that are coated with an almost white-looking powder.
Knotweed Inspection
Knotweed should be inspected after the weed has grown to a more noticeable size by about the middle of summer. Search along sidewalks, driveways, and other paved areas near your grass. Sunny areas that have access to lots of moisture are one of this plant's favorite places to set down roots. If you live in a home near a river, ditch, beach, or creek, Knotweed can be easy to spot, as it loves those conditions.
Knotweed will begin to become more wiry and tough as it develops its taproot. If you discover Knotweed and its taproot early on in the spring or early summer, you may be able to eliminate it and prevent it from spreading by simply hand-pulling it.
Control Knotweed
How To Get Rid Of Knotweed
The best time to apply herbicide and treat Knotweed is during its active growth stage during the summer months. We recommend a potent, selective herbicide such as Quincept Selective Herbicide or Quali-Pro MSM Turf Dry Flowable Herbicide with Alligare 90 Non-Ionic Surfactant. These products can be used to kill the weed without damaging your turfgrass and other plants.
In more severe cases, it may require a non-selective herbicide before this weed is completely eradicated.
View our safe products for your specific variety of grass:
Knotweed Selective Herbicide Recommendations
Quali-Pro MSM: Quali-Pro MSM Turf Herbicide is a powerful post-emergent herbicide for turfgrass control, helping lawn owners take on undesirable weed species like Knotweed, Bahia grass, Foxtail, Ryegrass, and Virginia Button. This treatment has been specifically designed to tackle even the most stubborn of weeds while remaining safe for Bluegrass, Bermuda Grass, and St. Augustine varieties. This herbicide's active ingredient, Metsulfuron Methyl 60.0%, allows you to effectively control grassy and broadleaf weeds in your turfgrass.
Alligare 90 Non-Ionic Surfactant: You can give your weed killer's a huge boost in effectiveness with a quality surfactant. The Alligare 90 spreader/sticker, when mixed with ½ ounce per gallon of herbicide, helps ensure that chemicals stick to the targeted plants and make more of an impact.
Non-Selective Herbicide Recommendations
Warning on non-selective herbicides: Non-selective herbicides will kill both desirable and undesirable plants, so you'll need to be cautious during application.
Agrisel Gly Pho-Sel Pro 41%: Agrisel Gly Pho-Sel Pro is a non-selective weed killer for professional landscapers and homeowners. Featuring 41% glyphosate and 15% surfactant, it provides fast-acting results, eliminating broadleaf weeds from your lawn or garden. Apply glyphosate herbicides for control over even the most difficult weeds and unwanted vegetation.
Knotweed Prevention
After you've gotten rid of this invasive weed from your lawn or garden, the last thing you want is for it to return again in several months or the next year. Since Knotweed is an annual weed, we recommend you apply pre-emergent during late fall, as it will begin to germinate at the end of February or at the beginning of March.
Growing a healthy turfgrass is crucial to crowding out Knotweed and many other broadleaf weeds.
Recommended Knotweed Prevention Products
Weed Beater Complete Granules: Great for warm and cool weather, Weed Beater Granules work as both a pre and post-emergent herbicide for broadleaf weeds, sedges, and annual grasses. It works best as a pre-emergent but provides ample suppression of emerged weeds as well.
Do-It-Yourself Pest Control Can Help You Eliminate Knotweed
If you're looking for an effective and straightforward method of eliminating Knotweed, look no further than Do-It-Yourself Pest Control. We offer a wide range of weed control products, including herbicides specifically designed to get rid of tough weeds like Knotweed.
If you have any questions about Knotweed or lawn care in general, please reach out to our team of experts! Our lawn care DIY professionals are happy to provide advice on how to keep your lawn looking beautiful throughout the entire year.