What is Phragmites?
Invasive Phragmites is native to Eurasia. It has been present in North America for at least 300 years, probably introduced accidentally in ballast material in the Maritimes. In 1916 it was observed along the St. Lawrence River in Ontario. In 1948 it was found at Walpole Island, in Lake St. Clair. Rapid spread of Phragmites in the 20th century was probably related to construction of railroads and major roadways, habitat disturbance, shoreline development and pollution. This robust grass is now established in most Lake Erie and Lake Huron wetlands and is becoming increasingly prevalent in Lake Superior coastal habitats. It was not until 2005 that Agriculture and Agri-food Canada identified Phragmites as the nation’s “worst” invasive plant.
Where did it come from?
It is not clear how Phragmites was transported to North America from its native home in Eurasia. However, ships dumping their ballast water may have been a contributory source by spreading seeds and plant parts. Phragmites reportedly was also used as dunnage for ship’s cargo that would have been dumped once the cargo was removed potentially contaminating the areas where dumped.
How long has it been here?
Invasive Phragmites has been damaging ecosystems in Ontario for decades, starting in the Walpole Island area in the 1940’s and spreading into Southern and most recently, Northern Ontario.
How does it spread?
Seeds
- up to 2000 seeds per head
- can be dispersed up to 10 kilometres by the wind
- also spread by water, wildlife, heavy equipment and unknowingly by people using it for ornamental purposes
Rhizomes and Stolons
- once established spreads predominantly underground via rhizomes; dense clones-200 stems per square metre; rhizomes observed at 10metre depths
- also spread along the ground surface via stolons; observed at 10 metres in length, with new plants every 30 centimetres
- fragments of rhizomes and stolon that break off and are transported to other areas along the shoreline, and down waterways can regrow
Phragmites is known for its exponential growth in colony size and its ability to establish quickly in disturbed sites.
Why should I care about it? Why not just let it grow?
- Phragmites is damaging Ontario’s biodiversity, wetlands and beaches.
- Phragmites crowds out native vegetation resulting in decreased native plant biodiversity.
- Phragmites provides poor habitat and negatively impacts food supplies for wildlife, including several Species at Risk (For example, turtles have become trapped in thick Phragmites and have died).
- Phragmites grows very quickly thereby causing lower water levels as water is transpired faster than it would be with native vegetation.
- Phragmites is a fire hazard. Stands are composed of a high percentage of highly flammable dead stalks. In places where Phragmites is prevalent there are often reported cases of fires causing damage to homes and properties.
- Phragmites can affect agriculture, cause road safety hazards from blocked intersections and impact recreational activities such as swimming, boating, hiking, birding and angling. Many lake front cottages and campgrounds have lost their beaches resulting in decreased property values. Recreational beaches can become inaccessible due to thick, high stands of Phragmites growing along the shoreline. When dried stalks break off, the short stalks become sharp spikes making the area hazardous to walk through without adequate foot protection.
I have Phragmites on my property. How do I get rid of it? Can I just cut or mow the Phragmites?
Repeated mowing will stress the plant but will not destroy the root structure. Mowing may in fact increase root activity. Mowing in environmentally sensitive areas is not encouraged due to the threat to wetland-dependent species.
Spading underground roots has been effective in coastal dunes and at the sediment level in wet sites where Phragmites is sparse. Refer to http://opwg.ca/best-management-practices-factsheets/ for visual instructions on spading.
Spading underground roots has been effective in coastal dunes and at the sediment level in wet sites where Phragmites is sparse. Refer to http://opwg.ca/best-management-practices-factsheets/ for visual instructions on spading.
Who do I contact for Phragmites removal?
Residents of Lambton County may be able to have large stands of Phragmites on DRY LAND removed chemically. Please contact the Ausable Bayfield Conservation Authority at http://www.abca.on.ca or 1-888-286-2610 or St Clair Region Conservation Authority at http://www.scra.on.ca or 519-245-3710
Please note there may be a cost to you for this service.
Please note there may be a cost to you for this service.
Can I burn standing Phragmites on my property?
Once dried, dead stalks should be cut and burned. Please check Municipal by-laws for more information.
Only trained professionals should burn standing Phragmites as the dried stalks are highly flammable.
Only trained professionals should burn standing Phragmites as the dried stalks are highly flammable.
Does Phragmites have any natural predators?
In North America, invasive Phragmites has no known natural predators so human intervention is required for control. While there are currently no bio-controls available for controlling widespread invasive Phragmites in Ontario, there are several pilot projects currently underway involving the controlled release of two types of moths. These are being released in small test areas, and the results are monitored. In Eurasia, these naturally occurring moth species bore into Phragmites stems, weakening or killing them in the process, thereby controlling Phragmites’ spread. Preliminary results here are positive, but it will be many, many years before this control method becomes effective for wide-scale Phragmites management.
More information about Phragmites
Negative effects of Phragmites
