A grass with invading power
Native to Eurasia, the Common Reed (Phragmites australis), is very invasive. It was introduced to the province of Quebec in the early twentieth century. It then spread along major highways in the 1960s and 1970s. The Common Reed can be found throughout large parts of the province.
When this plant settles into an area, usually a wetland, near ditches, streams and lakes, it literally invades it. When it is not controlled, it spreads and establishes a monoculture, pushing all other plants into other environments. This monoculture compromises native species that struggle to resist this invader.
In addition, the presence of a dense colony hinders human activities such as swimming and boating.
Interesting fact: a single reed can produce 1,000 to 2,000 seeds. In a reed bed (colony of reeds), there can be, on average, 300 stalks per square meter. Consequently, the colony can advance several meters into a new area within a few weeks. Also, a stalk can grow up to 4 cm per day!
You must repeat the following steps until the plants are eradicated:
Mowing: Cut the stalks and retrieve them. Young shoots can be mown to at least 1 cm above the ground every two weeks, from spring to fall. This will deplete the plant’s reserves and prevent it from producing seeds.
Sheeting: After cutting the stalks and young shoots, you can install a dark colored plastic sheet over the entire colony. Leave the cover in place for a minimum of 6 months. The heat and lack of light will eventually kill the plants.
Once the colony is eradicated, it is very important to plant indigenous trees and shrubs. These plants will compete and produce shade, which will hinder the re-growth of the reed.
It is very important to dispose of the Common Reed by either, drying and burning it or by putting it into airtight plastic bags and sending it to a landfill site, as a single small plant fragment is enough to regenerate a new shoot.
Resist the urge of using this plant to decorate your home
This practice is especially common around Halloween. The eradication of this invasive plant is a long term project, which is why it is very important to pay particular attention to how it propagates (by fragmentation, by its rhizomes and by its seeds).
Prevention is our best offense against the spread of invasive alien species.
For additional information, you can consult the leaflets on the Common Reed issued by Nature-Action Quebec.