Regulations (pertaining to the Great Lakes region) Jurisdiction | Regulation | Law | Description | Date Effective |
Illinois | Other | 515 ILCS 5/20-90 | This species is not on the Illinois Aquatic Life Approved Species List and if it is not otherwise native to Illinois it is illegal to be imported or possessed alive without a permit. | 7/9/2015 |
Indiana | Prohibited | 312 IAC 18-3-25 | It is prohibited in Indiana, making it illegal to sell, gift, barter, exchange, distribute, transport, or introduce this species | 9/8/2021 |
Michigan | Restricted | Natural Resources Environmental Protection Act (Part 413 of Act 451) | It is restricted in Michigan and is unlawful to possess, introduce, import, sell or offer this species for sale as a live organism, except under certain circumstances. | 3/21/2019 |
New York | Prohibited | 6 NYCRR Part 575 | It is prohibited in New York and cannot be knowingly possessed with the intent to sell, import, purchase, transport or introduce nor can any of these actions be taken. | 3/10/2015 |
Ohio | Prohibited | Ohio Administrative Code 901:5-30-01 | In Ohio, no person shall sell, offer for sale, propagate, distribute, import or intentionally cause the dissemination of this species. | 1/7/2018 |
Ontario | Restricted | Invasive Species Act, 2015, S.O. 2015, c. 22 - Bill 37 | It is restricted in Ontario, making it illegal to import, deposit, release, breed/grow, buy, sell, lease or trade this species. | 11/3/2015 |
Pennsylvania | Other | NA | This species is listed as invasive in Pennsylvania, however, no specific regulations are defined. | NA |
Wisconsin | Restricted | Chapter NR 40, Wis. Adm. Code | In specific counties in Wisconsin this is a restricted species and there is a ban on the transport, transfer and introduction of this species, but possession is allowed. For the remaining counties, its is a prohibited species and possession is also banned. | 4/1/2017 |
Regulation table last updated 7/05/2022. Always check federal, state/provincial, tribal and local regulations directly forthe most up-to-date information.
Control:
Few control techniques for Phragmites australis subsp. australis are fully effective used alone, and reinvasion is likely when the management strategy is not maintained. Which control methods should be used for a particular site will depend on the current conditions and management goals. Effective control is likely to require multiple treatments using a combination of methods. If a population can be controlled soon after it has established chances of success are much higher because the below-ground rhizome network will not be as extensive. It is often necessary to do repeated treatments for several years to prevent any surviving rhizomes from re-sprouting (Avers et al. 2014).
Biological
At this time no means of biological control are approved in the United States for eradicating Phragmites australis subsp. australis infestations. Literature reveals an abundance of herbivores on Phragmites outside North America, particularly in Europe (Tewksbury et al., 2002). Researchers have found 201 species (164 insects, 7 mites, and 30 fungi) associated with Phragmites outside North America, and there appear to be several promising biological control candidate species from Europe (Tewksbury et al., 2002). Researchers at Cornell University have been studying several of these insects native to Europe as potential biocontrol agents (Blossey, 2007 and Blossey et al., 2002). Based on the biology and ecology of Phragmites in North America European rhizome feeders are being given the highest priority as a biological control agent because it is anticipated that attack of below ground rhizomes will kill aboveground shoots, therefore reducing storage reserves and recovery potential, and disconnecting rhizomes, further reducing the competitive ability of Phragmites (Tewksbury et al., 2002). None are currently an option available to land managers, because some prospective control agents may do greater damage to native lineage of Phragmites than the invasive (Silliman et al., 2014). The moth species A. geminipuncta and A. neurica have been shown to be a potential biocontrol for Phragmites showing a strong preference to invasive over native species and minimal to no impact on plants outside of the genus (Blossey et al., 2018). A petition to release the two moth species was approved in Canada in 2019. The first biocontrol program using A. neurica and L. geminipuncta began in southern Ontario in summer 2019 (Ontario Invasive Plant Council, 2023). Current biocontrol strategies do pose a significant risk to native species (Cronin et al., 2016). Other studies have indicated that it is possible to control invasive Phragmites in North America via purposeful livestock grazing and that this method has a high potential to suppress its impact on native plant communities (Silliman et al., 2014). This is a viable option because livestock can persist over a relatively short time period (i.e., weeks to months) on a Phragmites-centered diet without negatively impacting their health (Silliman et al., 2014). While long-term, low-intensity grazing by goats and cattle has shown to decrease Phragmites density, it does not impact the root system. In fact, grazing at the wrong time of the year can increase Phragmites stem density (Great Lakes Phragmites Collaborative, 2015). It is also important to consider and investigate the potential for livestock grazing to impact non-target organisms and ecosystem functions (Silliman et al., 2014).
Physical
Mechanical methods must always be used carefully to avoid stimulating growth of Phragmites (Avers et al. 2014). Prescribed burning in combination with herbicide treatment, may be an effective control technique (Saltonstall 2005). Burns should be conducted the year following herbicide treatment, either in late summer (mid-July through August) or winter (January until prior to spring green-up (Avers et al. 2014). Burning in the winter can also be effective prior to herbicide treatment as it improves herbicide coverage by reducing the amount of standing dead biomass. Plants should not be burned in the spring or summer before flowering as this may stimulate growth (Getsinger et al. 2007). Some experts suggest that use of fire alone may stimulate rhizome growth and cause the remaining population to become more vigorous (Avers et al. 2014). Burning after herbicide treatment reduces standing dead stem and litter biomass, which may help to encourage germination of native plants in the following growing season (Saltonstall 2005). Burning also makes it easier to locate and re-treat areas of regrowth (Avers et al. 2014). A secondary treatment of rolling, burning, or cutting can increase litter decomposition rates, increasing the ability of native plants to establish (Yuckin et al., 2022).
Mechanical control (e.g., weed whips, mowers, brush hogs, flail mowers, hand cutting) may be effective at slowing the spread of established stands but is unlikely to be successful in eradicating a stand if not used in concert with herbicide application (Saltonstall 2005). Mechanical cutting and removal of Phragmites may be beneficial in the early summer before seeds have matured to prevent unwanted spread (Great Lakes Phragmites Collaborative). Mechanical control should be conducted to minimize soil disruption, which encourages re-sprouting (Avers et al. 2014). Excavation of sediments may be effective at control but if small fragments of root are left in the soil, they may lead to reestablishment. Once an area has been mowed, thatch should be raked, bagged and disposed of in an appropriate location to prevent seed dispersal and to allow sunlight to reach the soil surface (Avers et al. 2014). This allows the native seedbank an advantage in the subsequent growing season. When used in combination, mechanical control should not occur until at least 2 weeks after an herbicide treatment to maximize mobilization of the chemical to the root/rhizome system (Avers et al. 2014). Care should be taken to clean all equipment used for mechanical removal prior to transportation from the treatment site (Great Lakes Phragmites Collaborative 2015). Mechanical control of Phragmites works best in areas where it is fully inundated for several months in the 2 year period after slashing, but if the area is not fully inundated then it can recover almost completely within 10 months (Greet and Rees, 2015).
Cutting Phragmites while it is underwater, known as “cut-to-drown” can also be used as a control method for invasive Phragmites. This method effectively drowns the plant by removing its access to oxygen and can be utilized on large or small scales based on the available machinery. Cutting underwater is most effective during the main growth phase, which occurs in mid-spring to late summer, or in the translocation phase between late summer to mid-fall (Great Lakes Phragmites Collaborative, 2023).
Flooding stands of Phragmites can be used as part of a multi-method management approach in wetlands where managers have control of water levels. Managers often use this approach in wetlands with installed water management systems such as dikes. Flooding is only an effective management option if the entire stand is underwater for an extended period of time. The amount of water needed to cover Phragmites in a flood varies. It is suggested that water levels be maintained at a minimum of 1.5 meters (~5 feet) above the Phragmites stand, although shallower water depths are likely to still be effective as long as all parts of the plants remain submerged (Ontario Ministry of Natural Resources 2011, Great Lakes Phragmites Collaborative, 2023). It may take anywhere from 2-6 weeks (depending on water clarity) of consistent flooded conditions for the Phragmites stand to fully die back (Ontario Ministry of Natural Resources 2011, Great Lakes Phragmites Collaborative 2023). Flooding is most effective during Phragmites’ growing phase (mid-spring to late summer). Traditional drawdowns producing mudflats in early summer (as used to control other invasives) encourage the growth of Phragmites and should be conducted with extreme caution if Phragmites is present in the surrounding landscape (Avers et al. 2014). In some cases alternate flooding can even increase Phragmites growth (Li et al., 2017).
Covering cut stems with black plastic blocks light and increases temperature which will eventually kill Phragmites below the plastic, however, the plastic can break down quickly having unintended negative ecological impacts (Great Lakes Phragmites Collaborative, 2015). This method has shown to be effective in small areas that previously received direct sunlight and could be ideal in locations where use of herbicide would impact nearby native plants (Great Lakes Phragmites Collaborative, 2015). Solarization also reduces seed density after the first year of treatment but the decreases did not continue into future years (Rohal et al., 2021).
Chemical
There are several effective chemical treatments for managing Phragmites, but it is important to be aware of potential secondary invasions that can occur. The treatment of Phragmites at Long Point peninsula in Lake Erie led to a secondary invasion of the invasive species Hydrocharis morsus-ranae (European Frog-bit) (Robichaud and Rooney, 2021). Areas with large, established populations of Phragmites are best restored using herbicides. Chemical control is particularly effective when used in combination with prescribed burns, or other types of mechanical removal (Avers et al. 2014, Great Lakes Phragmites Collaborative 2023). Summer mowing followed by an herbicide treatment had the highest effect out of 6 tested treatments and created the best conditions for native plant recruitment (Rohal et al., 2019). Chemical techniques need to be carefully applied so that all fragments of a Phragmites stand are killed (Great Lakes Phragmites Collaborative 2015). If the entire clone of Phragmites is not killed, then the remaining rhizomes may produce new stems the following year (Great Lakes Phragmites Collaborative 2015). It is often necessary to do repeated treatments for several years to prevent any surviving rhizomes from re-sprouting (Avers et al. 2014).
Glyphosate and imazapyr are two broad spectrum herbicides commercially available and known to control Phragmites (Avers et al. 2014). These herbicides are best applied in late summer/early fall after the plant has flowered, either as a cut stump treatment or as a foliar spray (Avers at al. 2014). Together, glyphosate and imazapyr were found to be the only herbicides that resulted in greater than 90% biomass reduction of Phragmites australis in controlled mesocosm studies (Chesier et al. 2012). Herbicide treatments may need to be repeated for several consecutive years before a significant reduction in seed density is observed and to avoid secondary invasions (Rohal et al., 2021 and Jordan, 2022 ). However, it must be noted that these chemicals are nonselective and will impact native plants if they come in contact with the herbicides. It is of the utmost importance to apply these chemicals carefully at the recommended levels. Always read the herbicide label prior to use to determine the appropriate application rate and re-entry times. Improper application of terrestrial formulations in aquatic environments may harm fish and macroinvertebrates and is a violation of federal and state laws. Both herbicides are available in separate formulas for application either on aquatic (wet) or terrestrial (dry) sites (Avers et al. 2014). Glyphosate and imazapyr can be used individually or combined as a control strategy for Phragmites. Visual effects, such as browning or withering of the plants, may not occur for several weeks (Avers et al. 2014). A rope wick application can be better at controlling Phragmites with lower and more targeted application rates reducing environmental contamination (Al-Wagaa et al., 2019).
Imazapyr should be applied to actively growing green foliage after full leaf elongation. If the stand has substantial amounts of old stem tissue, allow new growth to reach approximately 5 feet tall before treatment. Imazapyr is highly effective on controlling Phragmites, as it acts slowly and can remain active in the soil during the following year or more (Aver et al. 2014). Imazapyr may persist actively in the soil for multiple years so it is not recommended for treatment in areas with high floristic quality and/or diverse native vegetation (Avers et al. 2014).
Glyphosate should be applied after plants are in full bloom in late summer (Avers et al. 2014). Glyphosate is not as effective as imazapyr; however, it costs less and has good results with follow-up treatment or where water level management is available (Avers et al. 2014).
Hazelton et al. (2014) reviewed Phragmites literature to see where gaps lie in management of this invasive species. This review suggests that (1) management efforts should be shifted towards restoring native plant communities rather than just eradicating Phragmites stands, since a healthy native plant community can better withstand Phragmites invasion, (2) management needs to switch to watershed-scale efforts in coastal regions and/or larger management units inland as Phragmites are not restricted to the Great Lakes coastline, and (3) wetlands and watersheds should be ranked to identify ecosystems that would most benefit from Phragmites eradication to insure efforts are best utilized.
Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.
For more information on management of invasive Phragmites in the Great Lakes region, plase visit the Great Lakes Phragmites Collaborative.