Water gardens

Riparian Buffer: To Mow or Not to Mow?

Do you have a riparian buffer on your property? Should you mow it in the fall? Cover it? Mow it?

Bande riveraine sur le bord de l'eau
Photo: Alexey Komissarov

Whether you’re a farmer or a lakeside cottage owner, your riparian buffer strip is doing you a huge favor, and you’ll be doing the environment a favor too if you take care of it. If you’re not sure what to do with this little piece of nature in the fall, this article is for you!

The Services the Riparian Buffer Zone Provides for You as a Homeowner

You like to enjoy the view of your lake, your dock, the sound of the water. But did you know that growing three meters of vegetation along your shoreline is the best thing you can do to secure your property? Already, if you have brambles or other prickly plants, nasty thieves will think twice, and spring floods and landslides can be enormously reduced with good waterside vegetation.

How Does a Riparian Buffer Work?

In spring, plants awakening from dormancy, or new shoots of annuals, are thirsty and absorb large quantities of water. What’s more, the sturdy roots of trees, shrubs and other large perennials act like a grid that holds the soil in place.

Imagine the bottom of your sink: if you empty a glass of water into it, it flows down the drain, symbolizing your watering hole. The deep layers of the ground are similar: water trickles down and flows towards the river or lake.

Put a layer of sand in your sink (but not for real!). Do it in your imagination. I don’t want to get your plumbing bills!) As soon as you pour water from your glass, the sand will flow down the drain too. That sand represents your soil… and possible landslides or shoreline erosion.

Now imagine putting lots of wool in your sink, sand, then water. And voila, a floor that doesn’t drain, that absorbs lots of water, and that’s a much more solid foundation for your home!

It’s a rather strange comparison, I grant you, but I think the image is clear. Landslides and excess water can be greatly mitigated by mature vegetation on your property.

The Services the Riparian Buffer Zone Provides to You as a Grower

If I continue my root-foundation story, you should know that the smallest roots of shore plants also play a role in holding the soil together. They’re like a net that holds the soil together, as well as the edge of your field, which is more than necessary if you’re growing near water.

Shoreline erosion is a big problem when you’re farming: who wants to see their land reduced, year after year, because of soil washed away by rain and current? Besides, annual crops like corn aren’t the best to grow near water if you don’t have a nice vegetated shoreline, since the soil, without any root net, will erode even faster in spring! However, a good riparian strip can help keep fields from losing their soil, and prevent flooding of plants near water.

Photo: Tom Fisk

Another benefit of a healthy riparian buffer zone is that it attracts nature to your crops. Why is this good for you? A balanced ecosystem attracts a host of useful animals: insect pollinators, soil recyclers and even predators like toads, snakes and birds. Why spend money on pesticides if nature can find a balance and get rid of pests naturally?

What Your Riparian Buffer Zone Gives to the Environment

You don’t want to lose a few inches of your land per year to erosion? Well, neither does nature!

Shorelines are very important for many species, and soil that “falls” into the water isn’t necessarily a good thing either. When soil isn’t retained, rainfall runoff carries much of the soil’s nutrients and contaminants… directly into the water. This is a major source of pollution that a simple root net can stop.

Avantages bande riveraine pour l'environnement
Photo: Radoslaw Sikorski

Riparian plants eliminate a lot of water pollution, as well as being important CO2 collectors. You know, the nasty gases responsible for climate change that damage crops? Yeah, ecology’s like that: everything’s connected.

If the riparian strip is a habitat for many terrestrial animals and amphibians, it’s also indispensable for many aquatic species: fish sometimes need these grassy environments to hide, lay eggs or feed. I don’t know about you, but I love sushi, so take care of the fish and don’t put too many pollutants in the water, okay? I’m giving you my suspicious eyes here!

With all these arguments, I think it’s worth taking care of your shoreline, don’t you? Raise your terrace a bit to get a nice view, agree to give a few meters of your land to the environment, and you’ll be able to enjoy the sound of frogs singing in the evening, all the while bragging about being super green.

Photo: Vojta Kova?ík

How to Maintain Your Shoreline to Get the Most Out of It for Us and Nature

In an ideal world, wetlands, which are so important to the balance of nature, would remain untouched. These environments are perfectly self-sufficient, and you don’t need to “help” them in any way.

Even so, pruning may be necessary in certain cases: for example, if you have a dock, you can, armed with shears, prune either side to prevent it from being overgrown.

For growers, it can be a little more complex. Some crops, for example, can be extremely sensitive to the presence of more invasive wild plants. At such times, mowing the riparian strip before these “weeds” go to seed may be enough to limit the damage. Ideally, this should be done from the second half of July onwards, to give country birds, which often nest on the ground, a chance to finish their broods. It is recommended that you leave your riparian strip about 30 cm high when mowing.

Barn swallow (endangered in Canada). Photo: smuller
Short-eared owl (likely to be designated threatened in Quebec and threatened in Canada). Photo: jadenbarney1234
Bobolink (vulnerable in Quebec and threatened in Canada). Photo: j-j

If you want to attract pollinators, you should mow in late August, but not before.

Otherwise, Don’t Touch ANYTHING!

NEVER mow a riparian buffer strip! Under NO CIRCUMSTANCES do you remove rocks or dead wood from it. And above all, NEVER, UNDER ANY CIRCUMSTANCES, throw waste into the water, and that includes the clippings from your mowing. Instead, leave them in your field or lawn and they’ll decompose, adding fertilizer to your soil.

Lawns are rich in nitrogen, which contributes to the proliferation of algae causing eutrophication. Eutrophication? The death of lakes overflowing with algae. Oxygen and light run out because of too many algae, and everything dies because of this imbalance… So keep your clippings on the ground, my dear laidback gardeners!

In short, what do you do in autumn? NOTHING! A bonus for the laidback gardener!

You’ll forgive me if I’m not as funny as usual, but we’re not kidding about riparian buffers! Canada is so rich in beautiful wetlands, and freshwater is such an important and easily accessible resource, that we tend to take it all for granted.

Audrey Martel is a biologist who graduated from the University of Montreal. After more than ten years in the field of scientific animation, notably for Parks Canada and the Granby Zoo, she joined Nature Conservancy of Canada to take up new challenges in scientific writing. She then moved into marketing and joined Leo Studio. Full of life and always up for a giggle, or the discovery of a new edible plant, she never abandoned her love for nature and writes articles for both Nature sauvage and the Laidback Gardener.

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