Japanese Knotweed Expert recommend five treatment visits, conducted over one growing season, and then five subsequent inspection visits over the following 2-3 years.. Each herbicide treatment is bespoke and should consider the proximity of the knotweed to waterways or any non-invasive plants or weeds growing in the near vicinity. & Zucc.) They are all glyphosate-based herbicides and will kill the troublesome weed. The herbicide treatment is most efficient on a warm, sunny day. The best time for Japanese knotweed to be sprayed is when the plant is actively growing as the herbicide we use is a systemic translocating herbicide. By being a cost-effective way of controlling knotweed, the gallon herbicides can effectively cover an area of more than 25,000 square feet. While you could always use a glyphosate herbicide such as Roundup, this can be harmful to the environment. This herbaceous plant (sometime referred to … View on Amazon. One example of a cultural control method for knotweed is preventing the spread of rhizome pieces in soil and on excavation equipment. This DIY Japanese knotweed killer recipe works best to get-rid-of-Japanese-knotweed when used in the summer or early fall, and is not as slow as a homemade duckweed killer you may use in a pond. Herbicide treatment for Japanese knotweed. preventive weed control. NMISN* advises 3-7 oz/acre and MMSI** uses 6-10 oz/acre. Roundup, Gallup, Landmaster, Pondmaster, Ranger, Rodeo, and Touchdown are all herbicides recommended to kill Japanese Knotweed. However, Japanese knotweed The most common and preferred treatment method is a herbicide treatment. At first sight, the plant's small, … It is native to Asia, and was originally introduced to the U.S. as an ornamental in the late 1800's. See our Written Findings for more information about Japanese knotweed (Polygonum cuspidatum). 1/2% Cygnet Plus (D-limonene) = 0.6oz/gal spray solution Foliar spray or "cut stem" application (cut down stems and fill the stem cavity with herbicide Evaluation of Imazapyr, Glyphosate, and Triclopyr for Japanese Knotweed (Polygonum cuspidatum Sieb. The Process. Japanese knotweed has come a long way since Philipp Franz von Siebold, the doctor-in-residence for the Dutch at Nagasaki, brought it to the Utrecht plant fair in the Netherlands in the 1840s. This particular type of herbicide poisoning treatment is the ideal solution for treating large and small areas infested with Japanese Knotweed. It grows in dense patches to heights of 10 feet, on sites ranging from strip mine spoil to shaded streambanks. The best approach to control is through a combination of cutting and herbicide application. WSDA Knotweed Control Program. 14oz/acre for Japanese knotweed. Japanese Knotweed Killer Recipe. The visceral response a patch of Japanese knotweed evokes in scientists, naturalists and homeowners might surprise you. Must measure sprayer output to calculate dilution of Milestone; see attached protocol for 6oz/acre rate Yes. Encouraging or establishing alternative groundcover provides competition to knotweed, and will enhance the effects of other treatments. The third is the Japanese knotweed herbicides on our list, as it is both Cost-effective and 100% Aquatic approved. Managing Japanese Knotweed Japanese knotweed (Polygonum cuspidatum) is an imposing herbaceous perennial that is commonly called 'bamboo'. A late spring/early summer treatment followed by an early fall re-treatment is needed. One popular Japanese Knotweed herbicide treatment method is the leaf application of herbicides, also known as foliage spraying. The best time to spray the leaves of Japanese Knotweed with herbicide is late summer or early autumn. 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