Invasive Phragmites, also known as Phragmites australis or European common reed, is a tall and robust

perennial grass species that has become invasive in many wetland and riparian environments around

Ontario. It is important to note that this description is based on its general characteristics and might not

cover all possible variations or regional differences. Height: Invasive phragmites can grow to impressive

heights, often exceeding 15 feet (4.5 meters) in favorable conditions. However, height can vary

depending on factors like local climate and soil conditions.

Invasive Nature:

The invasive nature of phragmites is attributed to its aggressive growth and ability to form dense stands,

displacing native plant species and altering natural habitats.

Its rapid spread can be facilitated by human activities, such as construction, altering water levels, and

transporting plant material to new areas.

Biodiversity Loss:

Invasive phragmites can form dense stands that crowd out native plant species. This reduces the

diversity of plant species in the wetland, leading to a loss of habitat and food sources for various

animals, insects, and microorganisms.

Altered Hydrology:

The dense growth of invasive phragmites can alter the natural hydrology of wetlands by impeding water

flow and reducing water retention. This can lead to changes in water levels, increased sedimentation,

and altered nutrient cycling within the wetland.

Wildlife Habitat Degradation:

The tall, dense stands of phragmites can create physical barriers for wildlife, making it difficult for them

to move within the wetland. Native wildlife that depends on open water or specific types of vegetation

may be displaced or negatively impacted.

Decreased Water Quality:

The altered hydrology and nutrient cycling caused by invasive phragmites can lead to decreased water

quality in wetlands. Increased sedimentation and nutrient runoff can result in eutrophication, leading to

excessive algae growth and reduced oxygen levels in the water.

Fire Risk:

Invasive phragmites tends to have a higher fire risk compared to native vegetation due to its dry and

highly flammable nature. Fires in phragmites-dominated wetlands can spread rapidly and have

destructive impacts on both the plant community and the surrounding area.

Loss of Recreational and Aesthetic Value:

Dense stands of invasive phragmites can reduce the visual appeal of wetlands, impacting their

recreational and aesthetic value for activities like birdwatching, photography, and other outdoor

pursuits.

Economic Impact:

Invasive phragmites can have economic consequences for industries such as agriculture, fisheries, and

tourism, as wetland degradation can affect the availability of resources and ecosystem services.

Habitat Modification:

The dense root systems of invasive phragmites can alter the physical structure of wetland habitats,

converting open water areas into marshy environments. This modification can impact the suitability of

wetlands for various plant and animal species.

Control Methods

Mechanical Removal:

Phragmites stands which are in a sufficient amount of water can be “cut to drown” with cane cutters,

brush cutters, or machinery below the water’s surface which restricts the plant’s access to light and air.

Subsequent cutting must be done repeatedly over several years in most cases in order to be effective in

the long term.

Herbicide Application:

Herbicides can be used to control phragmites, but their use requires careful planning and adherence to

regulations to minimize environmental impacts. Glyphosate-based herbicides are commonly used for

foliar spraying. Systemic herbicides are absorbed by the plant and work to kill the rhizomes as well.

However, non-target plants should be protected during application.

Prescribed Burning:

Controlled burns can be used to remove above-ground vegetation and some of the seeds, promoting

the growth of native species. Burning also helps to reduce the accumulation of dead plant material.

Burning should be conducted by professionals to ensure safety and prevent the spread of fire to

unintended areas.

Flooding Management:

Altering water levels can help control phragmites growth by creating conditions less favorable for its

establishment. Flooding can inhibit germination and growth, as well as encourage the growth of native

wetland species.

Restoration and Re-vegetation:

After invasive phragmites control, restoration efforts involve planting native wetland species to help

restore the ecological balance of the habitat, which can be particularly important to prevent phragmites

from re-establishing.

Monitoring and Adaptive Management:

Regular monitoring of treated areas is essential to assess the effectiveness of control methods and make

adjustments as needed. Adaptive management allows for refining strategies based on the needs of the

environment and control outcomes.