For larger populations, cut the plants in late June or early July, and then treat the re-growth with a foliar spray of a systemic herbicide in late August or early September. Since 2005, the Friends have used two experimental techniques in an attempt to eliminate knotweed from this area. Treatment with systemic herbicide can be effective, but you might need to treat repeatedly; another possibility is stem injection or application of a systemic herbicide to freshly cut stems, though this is labor intensive. Established populations have extensive root systems, so removal by pulling or repeated cutting is only effective for young plants. It’s not a true bamboo; it’s an aggressive member of the buckwheat family. John can be reached at jcblex@verizon.net, and additional information about Arlington’s Great Meadows can be found at www.foagm.org. Overview. Arlington’s Great Meadows (AGM) is a 183-acre tract of open land owned by the Town of Arlington and located in neighboring East Lexington. For communities that rely on fishing for tourism and income, knotweed infestations along waterways can result in economic loss by reducing fish populations. Japanese Knotweed is also commonly Eco-Answers from the Pros: Recommendations for Conifer Screening. Ideally landscaping provides not only aesthetic improvements, but protects and restores the existing systems that sustain us. If diluting, do so over a dry sandy or gravel area. Biocontrols are species selected from an invasive species’ … These have included repeated cutting, mulching, application of herbicide to freshly cut stems, and application of herbicide as a foliar spray. Japanese knotweed (Fallopia japonica) was brought from eastern Asia as a garden plant. This field is for validation purposes and should be left unchanged. Along highways and bike paths, human activities substitute for flooding as mowing and other maintenance activities can spread rhizome fragments along the corridor. Both approaches the Friends have taken, however – particularly the longer-term “Cut, Cut, Cut” method – are extremely labor-intensive and thus heavily dependent on the willingness of volunteers to contribute significant efforts over a sustained period of time to work that can be thankless, dirty, and at times downright Sisyphean. This ability to re-sprout from fragments – fragments as small as one inch – results in its rapid spread to new locations. It is also why it is so often seen lining waterways, roadways, and bike paths. Right side injected; left side foliar application – August 2008. In September 2008, all surviving knotweed was treated with foliar spray. The overall goal is to determine suitability of several insects as biological control agents. Could We Manage Backyards to Increase Biodiversity? Designed by Dr Eric Connelly and JKSL, the method does not use any chemicals, and therefore leaves the lowest possible on-site footprint where it is used. We don’t want to use anything that will affect our water, wells, or wildlife. Knotweeds. Both switchgrass and daylilies are fairly drought tolerant, requiring little or no irrigation for establishment. Japanese knotweed is legally prohibited in Michigan. Two separate projects, one by the Massachusetts Department of Transportation (MassDOT) and another by Friends of Arlington’s Great Meadows (FoAGM), are using very different strategies to restore small areas of knotweed-infested land. The family name of Polygonaceae is derived from the Greek words, “Poly” meaning many, and “goni” meaning knee or joint. In that case, they will be mowed. Using living organisms to control pests in this way is known as biological or natural control. We certainly can’t address all invasive plant populations in this way, nor, given the persistence of invasive plants, can we necessarily expect these designed landscapes to last any longer than a garden once the maintenance stops. One of the most frustrating aspects of landscaping is watching new plantings get overtaken by invasive plants. control methods to limit the growth of Japanese knotweed in the UK. Along roadways and bike paths, knotweed causes safety concerns when it blocks signs, sight lines, and walkways. FoAGM have been managing knotweed with volunteers and no herbicide at a site along the Minuteman Bikeway in Lexington, MA since 2004. The stems have a fine white coating that rubs off easily. The infrequent cutting of knotweed canes, which is typically the practice along highways or other minimally managed land (cutting only when it becomes problematic), instead of weakening the plants, may actually stimulate lateral shoot growth, increasing the spread on-site and to adjacent sites. Knotweeds (Polygonum spp.) The notion of the permanent removal of knotweed or other invasive species is a noble but naïve endeavor. are invasive perennials, with four species found in British Columbia: Japanese knotweed (Fallopia japonica); Bohemian knotweed (Fallopia x bohemica); Giant knotweed (Fallopia sachalenensis); and Himalayan knotweed (Polygonum polystachyum). But perhaps they are a small step in the direction of bringing about a much-needed cultural shift from perceiving landscaping as being solely for ornamental purposes to recognizing that landscaping is also about restoration. Unfortunately, this length of encapsulation does not seem to have been sufficient to completely eradicate the knotweed. Her responsibilities include design, design review, and construction services for landscape restoration on transportation projects, including upland restoration and wetland and stream bank mitigation. Of all the invasive species, Japanese Knotweed (Polygonum cuspidatum), once established, is one of the most difficult to manage and eradicate. Whether management can be sustained long enough or controls will be sufficient to allow for the establishment of the desired species, only time will tell. For large stands, such as that at Exit 14, the injection method is too time-consuming. In the spring of 2009, the dead knotweed canes were cleared, and the site was planted with one-gallon pots containing two varieties of switchgrass, ‘Shenandoah’ and the straight species, and daylilies along the edge. Japanese knotweed is easy to spot any time of year: its round, green-speckled, red-brown, inch-thick, hollow stems are thick and woody, standing tall even during the winter. Soll, Jonathan, The Nature Conservancy: Controlling Knotweed in the Pacific Northwest, 2004. Tara Mitchell is a landscape architect with Massachusetts Department of Transportation. Estimated Cost: $0 to 25. The loss of leaf litter and woody debris results in a loss of shelter for fish and invertebrates. Several methods have been employed to control Japanese knotweed on Mass Audubon wildlife sanctuaries. Regenerative Solutions for Resilient Landscapes, Business Practices Spotlight: Keeping Employees Satisfied, PEST ALERT: Pitch Canker on White Pine. Once uncovered, a mix of wild meadow grasses was sown to stabilize the soil. Non-essential cookies are also used to … The results that the Friends have achieved in AGM demonstrate that knotweed can successfully be controlled, weakened, and possibly even eliminated, without the use of herbicides. The inability of groundcovers and mosses to grow beneath the dense canopy of knotweed results in bare soils, leaving banks susceptible to erosion and causing siltation in stream beds, again, altering fish habitat. Stems that were missed grew back the following year. The main advantage of this form of control is that, once recognised, an effective natural enemy provides control of the pest indefinitely, without further cost or intervention. The flowers are arranged in spikes near the end of the stems that are small, numerous and creamy white in color. During a single workday in the fall of 2008, volunteers were able to uproot approximately 80% of the knotweed plants in the “Cut, Cut, Cut” area, including a significant portion of their rhizomes. The 2004 East Fork Knotweed Control Project: Results Data, May 2005. The goal is not one of food production or aesthetics alone, but to provide a more stable plant community that protects wildlife, waterways, and human infrastructure. The key to our approach was to understand the plant, in order to control it. Spraying The only herbicide approved for use in or near water which controls japanese knotweed is Glyphosate. The MeshTech method is an eco-friendly means of controlling the spread of Japanese knotweed. Skill Level: Intermediate. Gozart, Casey. In some instances, it’s by species already on the site or adjacent to the site; in too many instances, it’s by species that are brought into the site through nursery material, hay bales, mulch, or loam. We are The Invasive Plant Company, industry experts in the delivery of successful, cost-effective solutions for the control and eradication of Japanese Knotweed and other invasive plant species. It grows in dense patches to heights of 10 feet, on sites ranging from strip mine spoil to shaded streambanks. Eco-Answers from the Pros: Do I Need Mulch with Groundcover. The loss of tree and shrub canopy can cause increases in water temperature. MassDOT is maintaining a site treated with herbicide and restored with switchgrass along I-290 in Worcester. Knotweed treated in the planted areas consisted of small clumps with 20 to 30 live canes and larger clumps that were approximately 6 x 10 feet in size. Knotweed sprouts were manually pulled in the spring, and they were pulled again and spot treated with herbicide later in the season. Knotweed at Exit 14 prior to treatment – May 2007. As of August 2011, the switchgrass is establishing well. The garden committee proposed the … Invasive Species - (Fallopia japonica) Prohibited in Michigan Japanese knotweed is a perennial shrub that can grow from 3 - 10 feet high. Read More. Managing Japanese Knotweed Japanese knotweed (Polygonum cuspidatum) is an imposing herbaceous perennial that is commonly called 'bamboo'. The problem is not simply that of displacing native plants and altering upland and aquatic ecosystems. 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. The contract included planting in various locations and a small-scale experiment to test the effectiveness of selectively applying an herbicide (glyphosate) with an injection gun to eradicate knotweed in planting beds. The effort and the intent behind these two projects put them more in line with gardening than with what is typical for maintaining minimally managed landscapes such as roadsides, bike path corridors, or reservations. At that time, the switchgrass will be left to fend for itself. It was introduced to the United Kingdom from Japan as an ornamental in 1825 and from there to North America in the late 1800s. Unless pulled or re-sprayed, knotweed re-growth will likely overtake the daylilies. Humans not only spread knotweed by moving rhizomes from place to place, but our management practices may also be causing infestations to expand more rapidly. The Minuteman Bikeway, one of the most popular rail trails in the United States, follows the western border of AGM for nearly a mile and offers breath-taking views of AGM’s wetlands. Treatment without herbicides is environmentally safer and avoids the hassles of permitting and the need for licensed applicators. Chemical treatment is the only viable control. Over the course of the treatment period, project managers found that the injection method, while effective, has limitations. In the final assessment of treatment, the injection method proved to be an effective means of applying an herbicide to eradicate small clumps of knotweed. For larger populations, cut the plants in late June or early July, and then treat the re-growth with a foliar spray of a systemic herbicide in late August or early September. Donations to Mass Audubon are tax-deductible to the full extent provided by law. Tara may be reached at tara.mitchell@state.ma.us. How to identify Japanese knotweed.. As land becomes unstable and costly to restore, knotweed can decrease property values. The intent of the daylilies was to help demarcate for mowers the borders of the planted bed that should not be mowed. A decision was made to plant switchgrass as part of the two-year contract. A second, adjoining plot, left under wraps for three more years, and finally uncovered in late 2009, has fared better. Two experimental plots located in the center of the test area were initially excavated, then covered with black plastic in the spring of 2005. Because injecting the entire patch of knotweed at Exit 14 would have exceeded the amount of herbicide allowed per acre, a decision was made to treat half of the site using the injection method and to treat the remainder with a glyphosate foliar spray. Larger clumps continued to have some re-growth. Clark County Weed Management: Lewis River Knotweed Control Pilot Project 2004 Report. Fill trash bags with the Japanese knotweed you want to get rid of so it can be easily transported. Japanese Knotweed is a woody stemmed herbaceous perennial rhizomatous plant, and is a member of the Buckwheat (Polygonaceae) family. Observation in the year following treatment found that most of the small, isolated clumps of knotweed in planting beds were eradicated. Here the strategy is to encourage a sense of shared responsibility on the local level where a community participates in the removal of knotweed and managing the landscape over the long-term. Therefore, the strategy is to use the most cost-effective treatment in the short term (herbicides) combined with planting for restoration. The major challenge the Friends face if the experimental effort they began six years ago is to succeed over the long haul is to develop and maintain a significant volunteer corps of more than just a few who can carry on the work on a sustainable basis without risk of fatigue or burnout. Although invasive plants abound in many areas of AGM, during the last six years the Friends have focused invasive management efforts in a test area along the Bikeway, about 100 yards in length, where a massive stand of knotweed, apparently introduced during construction of the bikeway, had grown up to block the view of the wetland from spring through fall. FRIENDS OF ARLINGTON’S GREAT MEADOWS: Management of Knotweed without Herbicides. What eco-friendly ways are there for Japanese knotweed treatment? Prevent spread of Japanese knotweed. Arlington’s Great Meadows “before” condition – 2004. Switchgrass was chosen in the hope that its deep and extensive root system (reaching 9 feet deep or more) could compete with that of knotweed, and that the density of above-ground growth might shade out knotweed sprouts. As with gardening, the focus is on the cultivation of specific vegetation on relatively small plots of land – not vegetables or ornamental species, but native species or a diversity of species. Do NOT bring orphaned or injured wildlife to Mass Audubon wildlife sanctuaries. © 2020 Ecological Landscape Alliance. However, the new growth has been noticeably less vigorous, and most of it can be uprooted by hand with a relatively minimal effort. As a targeted application, the injection gun was considered to have the potential to eradicate new knotweed populations without impacting adjacent, desirable plants. The concentration of glyphosate required is very high: 4ml to 5ml of 100% glyphosate injected into each stem. Amenity Assured and also an active member of the Amenity Forum. The challenge then becomes finding volunteers and sustaining that volunteer effort for the long term. DRWA has produced, with the help of the Massachusetts Environmental Trust and CopyCat Print Shop of Greenfield, a brochure (in PDF format) that explains the identification and ecology of Japanese knotweed and the impacts of the plant on the environment. No herbicides have been used for either method. Control of invasive plants in wetlands is subject to the Massachusetts Wetlands Protection Act; check with the local conservation commission before implementing control measures. Japanese Knotweed Biological Control Japanese knotweed (Fallopia japonica) is an herbaceous perennial native to Eastern Asia. Maximum effect is best when the plant is sprayed during the flowering period. This section has remained largely knotweed-free for the last two years. Clearly, management of knotweed is a difficult undertaking. Every year, the Parks Division and contract crews remove non-native invasive plants such as Japanese knotweed, garlic mustard, black swallow-wort, glossy buckthorn and tree of heaven from public open spaces. This in turn affects water chemistry and fish habitat. Treatment with systemic herbicide can be effective, but you might need to treat repeatedly; another possibility is stem injection or application of a systemic herbicide to freshly cut stems, though this is labor intensive. Despite the promise of the “Cut, Cut, Cut” method, this approach has not yet resulted in the complete eradication of knotweed. Polygonum cuspidatum, commonly known as Japanese knotweed or Japanese bamboo, was introduced from eastern Asia in the late 19th century. It is hoped that continued repeated cutting will eventually weaken the relatively few remaining healthy plants and allow them to be removed as well. Along waterways it not only replaces riparian vegetation and reduces upland species diversity, but it also alters aquatic ecosystems in a variety of ways. The local control and eradication of an invasive species, however, is achievable with adequate aftercare and re-establishment of a native plant community. You can take organic weed-control measures to deal with Japanese knotweed to some degree (such as choking it out with tarps), but you have a better chance of getting rid of this menace if you compromise and supplement such efforts with the occasional use of an herbicide. Well-established knotweed is very difficult to control, and successful control will require a multiple-step 'control phase', and an ongoing 'maintenance phase' in the following seasons to … We’re also part of The LK Group of companies, providing expertise in a range of sectors within the environmental industry. Knotweed can cause structural damage to asphalt and concrete. Humans also spread knotweed to new locations through the transport of rhizome fragments in loam and mulch. The disturbance of flooding causes rhizome fragments to break away from the banks and wash downstream where they create new colonies. Of all the invasive species, Japanese Knotweed (Polygonum cuspidatum), once established, is one of the most difficult to manage and eradicate. After several successive years, it became apparent that knotweed plants that had been cut down two or three times each growing season were starting to weaken and could be pulled out by the roots (rhizomes) with relative ease. If the knotweed control failed, the use of herbaceous species allowed for the site to be easily mowed. You can reduce the volume you need to dispose of by burning the weed. Biological control is a cost effective, ecologically sound, and sustainable approach to managing widespread weeds. You must prevent Japanese knotweed on … Japanese Knotweed Brochure . Japanese knotweed ( Polygonum cuspidatum )—nicknamed Godzilla weed—is one of the world's most invasive plants. Japanese Knotweed is exceedingly difficult to eradicate by traditional means (it will sprout through asphalt). In wetlands, only apply herbicides registered for use in those areas. Washington State Department of Agriculture, Statewide Knotweed Control Program, Progress Reports 2005 -2010 (www.agr.wa.gov). Those plants that were more tenacious and could not be uprooted in the first volunteer effort, as well as remnants of rhizomes from the plants that were successfully uprooted, have continued to generate new growth. While a third year of treatment would have provided better control prior to restoration planting, MassDOT was limited by the contract schedule. How to identify, control and dispose of Japanese knotweed. The surrounding area has been mowed as part of regularly schedule roadside mowing, minimizing the risk of re-invasion. This method was applied at either end of the central test plots that were covered in plastic. Because land doesn’t come with a manual. A few man-days of work each season has largely eliminated most of the knotweed that was previously growing on the upper bank closest to the Bikeway and helped maintain control of the recurring growth on the lower bank adjoining the wetlands. If you are using Round up Concentrate Plus, use it straight. All vegetative waste, including both knotweed canes and root masses, has been disposed of in compost piles on-site, eliminating the possibility of infesting new sites. Japanese Knotweed Control Ltd Accreditations. MASSDOT KNOTWEED MANAGEMENT: A Case Study. Once introduced to a site, knotweed easily out-competes other vegetation to create extensive mono-stands, altering native or otherwise stable vegetative communities and habitat. Get ecological news and event updates in your inbox. However, this difference could have been due to the difficulty of spraying full-grown knotweed (6-8 feet in height) rather than the effectiveness of the injection method. (Healthy knotweed is virtually impossible to uproot by hand.) While all of the clumps were significantly reduced in size and vigor or completely eradicated, in some instances, control unfortunately opened the site up to colonization by other invasives, primarily bittersweet and crown vetch. — P.D.S., Agawam, MA. Mass Audubon is a nonprofit, tax-exempt charitable organization (tax identification number 04-2104702) under Section 501(c)(3) of the Internal Revenue Code. The “Cut, Cut, Cut” method, which requires less exhausting up-front work but more continuous effort over the years, has offered better promise. As with Poison Ivy, Glyphosate (Round Up) is the product of choice for Japanese Knotweed, and the timing is the critical factor in successful control. However, controlling the spread of knotweed by humans may be even more difficult than eradicating knotweed from a site. Knotweed Sprout in switchgrass – July 2011. The first was uncovered at the end of 2006, after remaining under wraps for a little over a year and a half. Japanese knotweeds (Reynoutria japonica, Reynoutria sachalinensis, and their hybrid Reynoutria X bohemica) are invasive plants that are infamously difficult to control and have negatively impacted ecosystems and economies in the US, Canada and Europe.For several years, researchers have sought to find a biocontrol for knotweed. Knotweeds thrive in roadside ditches, low-lying areas, irrigation canals, and other water drainage systems. Rotting rhizomes in “Cut, Cut, Cut” area. All Rights Reserved. While the organizations behind the projects and their means and methods are considerably different, ultimately, it is the similarities which make the efforts so far successful: sustaining long-term management (requires one or more dedicated individuals); staying within the limits of the resources available by focusing on small areas; and incorporating restoration as part of the control. Knotwood re-growth after first treatment. Minimal control of knotweed by pulling and spot treatment (depending on availability of applicator) is planned for another two years by which time the switchgrass should be dense and well-established. Control of Japanese knotweed is laborious and expensive. At the time, the injection gun was relatively new and was considered highly effective. Managing knotweed requires both on-site control as well as taking steps to prevent spreading it to new locations. Add enough dye so you will be able to tell where you have treated. In August 2009, with the end of the contract approaching, knotweed re-growth within the newly planted restoration was pulled and spot-sprayed. Step 1: Wearing appropriate safety gear, dilute the Cornerstone1:1 with water in a spray bottle. Identification/Habitat Japanese knotweed is a dense growing shrub reaching heights of 10 feet and looks like a bamboo. While it is too early to tell whether control methods that do not involve the use of herbicides can offer an effective long-term solution, the Friends’ efforts at the very least have succeeded in keeping open for thousands of cyclists and other daily users of the Minuteman Bikeway one of the finest views of the Meadows. As such areas inevitably require foliar follow-up treatment, the cost and time spent on injection is probably not worth the effort. In 2011, knotweed was again pulled and spot-treated in the spring. Small shoots of knotweed continue to persist, but so far, the switchgrass is holding its own. Knotweed spreads by seed, but its primarily means is vegetative – through its rhizomes (root system). Label bottle. The contract began with herbicide treatment in September of 2007. Let cut canes of Japanese knotweed dry out for a week or so, then burn them in a controlled setting such as a fire pit. Control not kill. The first, referred to as “Cut, Dig and Cover” or “Dig, Dig, Dig,” has involved cutting the stalks, digging out the root crowns and as much of the rhizome network as possible, and then covering the ground with black landscape plastic for an extended period of time in an effort to block sunlight and thereby destroy any remaining rhizomes. Get in touch today – 0161 850 1604. Follow-up monitoring is necessary and re-treatment should be expected, particularly for larger clumps. Compared with conventional foliar spraying, it is very time-consuming (and therefore more costly) since every live stem has to be injected. 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