Ontario-wide plan needed to combat invasive grass, says report

Article repurposed from http://blogs.windsorstar.com/news/ontario-wide-plan-needed-to-combat-invasive-grass-says-report

Sharon Hill

Jun 18, 2015 - 10:05 PM EDT

Last Updated: Jun 18, 2015 - 10:17 PM EDT

Ontario needs a provincewide strategy to combat Canada’s worst invasive plant that continues to take over wetlands and ditches, says a report to the Essex Region Conservation Authority.

“I’d be surprised if I could find a wetland in Windsor-Essex without phragmites in it,” the authority’s director of conservation services Kevin Money said Thursday. “It’s a constant battle but it’s a battle I think we should take on.”

Phragmites grown in the ditch along Malden Road in Windsor on Thursday, August 29, 2013. (TYLER BROWNBRIDGE/The Windsor Star)

Phragmites is an invasive grass that grows as high as five metres or more. It spread rapidly across Essex County in the late 1990s. It is a “grave concern” because it grows thick and takes over wetlands to the exclusion of all other kinds of plants and wildlife, Money said.

“This region has the highest number of species at risk in Canada and many of those are dependent on wetlands,” he said. “If we continue to do nothing, it means that there will be fewer and fewer populations of those species.”

Phragmites is extremely difficult to kill. The provincial government needs an Ontario-wide control strategy with associated funding and it needs to allow the use of herbicides that can be applied in areas with water, Money said. The authority doesn’t want to spray herbicides in wetlands but it is the lesser of two evils, he said.

ERCA successfully used a herbicide and then rolled down the grass and burnt it to kill the phragmites in 2009 and 2010 in the Ruscom Shores Conservation Area near Lake St. Clair because the wetland had dried up in low lake water levels. Once water was back in the wetland, the authority couldn’t use a herbicide that is allowed in the United States but not here, he said. The phragmites took over again.

Now Money’s report recommends a feasibility study to see if the authority can control phragmites in the Hillman Marsh Conservation Area in Leamington. That wetland offers a unique opportunity because ERCA has the ability to control the water level within three cells in the marsh. Raising the water level in one cell could drown the phragmites and allow native plants to re-establish.

Money said phragmites is a hazard for wildfires when it is dry in the spring and the thick stands clog drainage ditches which is bad for farmers. Phragmites spreads in the soil by sending out roots horizontally and spreads by thousands of seeds produced by the plant each year.

“Unfortunately, invasive phragmites has become so pervasive throughout southern Ontario that a comprehensive, large-scale, co-ordinated effort is now required to achieve any meaningful results,” the report says.

The report, which was approved unanimously by ERCA’s board Thursday night, also seeks to boost education about the invasive species and encourage municipalities to try to control the plant in drainage ditches.