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Frequently asked questions

1) Is the common reed native to Quebec?

The invasive common reed is exotic: it comes from Europe and was introduced to Quebec at the beginning of the 20th century. Quebec also has a native form of the common reed (originating in North America), but it is not very abundant and is not nearly as invasive as its European cousin. Close to 95% of the reed populations in Quebec are exotic.

2) How does the common reed propagate itself?

New reed populations arise essentially from seed, then spread vegetatively. The vast majority of new populations arise from one or more seeds. Next, the plant spreads underground via rhizomes or over the surface via creeping stems called stolons. The plant spreads quickest on moist soils with up to 1 m water, but can also spread on dry soils or in water up to 2 m deep.

3) Does the Ministère des Transports du Québec propagate the common reed?

The Ministère des Transports du Québec (Transports Quebec – MTQ) does not plant the common reed along roads and highways, nor does it propagate the plant voluntarily. However, road banks are ideal habitats for the plant, because they are humid, sunny and frequently disturbed. They are also favoured by the spreading of road salt during the winter as the plant grows better in the presence of salt. This is why the common reed is so abundant along roadsides in Quebec. The MTQ is well aware of the problem and has invested considerable sums into research on the common reed to find solutions that will prevent further spread of the plant.

4) Is it possible to halt further spread of the common reed?

We can stop the spread of the common reed by not creating good germination beds for the seeds and by shading sites vulnerable to invasion. Once established, the common reed is very difficult to eradicate. To prevent its establishment we must avoid creating good seed beds, that is, moist denuded soil surfaces. If this is not possible, such surfaces must be covered as quickly as possible with other plants such as grasses and shrubs which will cast shade thus preventing new seedling from establishing themselves. Creating shade is in general a good way to prevent the common reed from establishing itself, especially in drainage ditches or along waterways, as the plant is shade intolerant.

5) Is the common reed a threat to biodiversity?

Reedbeds (stands of reeds) have poor plant diversity. Up to a certain threshold, their impact on animals is low. Few plants other than reeds are found in reedbeds. However in fresh water marshes, these plant stands host a good diversity of fish, amphibians and birds. However, caution is needed: in Quebec, the reedbeds are not yet very extensive in marshes and it is possible that the impact of the plant on wildlife may be increasingly observed in coming years, as the plant expands its range.

6) Can the common reed damage public or private infrastructures?

Reed stems can sometimes infiltrate asphalt or pierce the liners of above-ground swimming pools. The stems that emerge in the spring from rhizomes are rigid and pointy and can thus, for example, pierce holes in swimming pool liners. This happens infrequently, but has nevertheless been sporadically reported across southern Quebec.

7) Can the common reed hinder agricultural crops?

For conventional crops (treated with herbicides), the common reed causes little or no problems. In fact, even a very tough plant such as the common reed cannot withstand repeated applications of herbicides such as glyphosate. On the other hand, for agricultural enterprises which do not use herbicides (organic farming), the common reed may become a real problem, because alternative weed control methods are generally inefficient for this plant.

8) Is the common reed useful in certain circumstances?

The common reed can increase road safety, purify water and stabilise banks. Along certain roads the common reed forms excellent traps which prevent the snow from blowing over the road. The reed is also a good water filter, particularly with regards to nitrogen pollution. Finally, the network of roots and rhizomes in the soil may help reduce soil erosion along banks. These advantages are however tempered by the invasive nature of the plant.

9) Is mowing an effective management tool?

Mowing will not alone eliminate a reedbed. On the contrary, mowing will stimulate the plant’s growth causing it to regrow even more densely. In theory, repeated mowing could exhaust the plant’s resources, but trials to date have been inconclusive.

10 ) Can herbicides be used to fight the common reed?

A single herbicide has been approved to fight the common reed in Canada (VisionMAX TM). This herbicide is based on glyphosate, and its use is strictly regulated. It can only be used in industrial, recreational or public areas, such as roadside right of ways. It therefore cannot be used on a residential lot, for example. Its use is also prohibited on waterbodies (drainage ditches, rivers, lakes, marshes, etc.).

Learn more about the common reed by consulting the articles or reports from the PHRAGMITES group which are available on this website.


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