Phragmites
Garden Clippings for July 16, 2022
Wild pigs are the latest entry on Ontario’s invasive species list.
Supposedly, wild pigs are a thing, and pose enough of a threat that they’ve managed to find their way on the invasive species list. The only pigs I have ever seen are those in a barn. And I have seen seemingly happy pigs on a tractor trailer, obviously unaware of what’s in store for them.
Wild pigs will never reach the level of concern of phragmites, which many experts are saying is Ontario’s worst invasive species. Phragmites is everywhere, spreading like wildfire, knocking out a host of native plants and animals in its wake.
The problem with phragmites is that it quickly turns a forest, meadow, or wetland, filled with plant diversity, into a monoculture where nothing else grows. Birds and wildlife that were once dependent on their host plants for food and shelter disappear as quickly as the phragmites advances.
Phragmites came to Canada long ago, when we first began trading with Europe and other parts of the world. As ship traffic increased, so did the arrival of phragmites.
For a short while, gardeners were not bothered by phragmites, because it had a few positive attributes. Phragmites grew quickly and gave instant privacy. Its glistening white plumes, appearing in fall, sway back and forth in the wind. And phragmites liked poor soil where little else grew. It performed especially wonderful in wet and swampy locations.
Aside from the ecological threat phragmites poses, the weed is becoming a serious nuisance in cities. Its aggressive roots penetrate drainpipes and field tiles. Stem growth is so rapid that fire hydrants and street signs are quickly buried. Phragmites is so thirsty that, like willows, they make less water available for others. Phragmites’ roots have been known to lift pavement and shift concrete walkways.
Perhaps Phragmites’s biggest danger is that once it is frozen, its stems dry up and become highly flammable.
Phragmites is not easy to get rid of. Cutting it off will do no good, because it spreads primarily through its roots. Phragmites has a growth habit like raspberries or sumac, with new shoots popping up near the existing parent plants.
Burning phragmites in a controlled burn makes good sense but doing so will not kill the extensive root system left behind. The herbicide Glyphosate is effective when applied in spring or fall when growth is active. Repeat applications will likely be necessary.
Conservation Authorities have found that the most effective method to eradicate Phragmites is a three-phase approach where spraying, mowing and burning is undertaken over a two or three year period.
You and I can do our part in reducing the spread of phragmites by cleaning our shoes and bicycle tires when we leave an infested area. If we are cleaning up phragmites stems, roots, or seeds, it is important to dispose of yard waste properly rather than composting it or moving it to other areas.
