Drought, disappearance of insects... How to help the planet, from your garden? More and more gardeners recommend no longer mowing, or at least doing a differentiated mowing, also called reasoned mowing. It is simply a matter of mowing only where necessary and letting the rest of the garden grow as you please. Our explanations.
Why is it recommended to let your lawn grow?
- To preserve the biodiversity of the garden
We often have the habit of mowing very often and very flush to have a "nice lawn". But the lawn, composed mainly of herbaceous plants and grasses, is home to many forms of life. "Tall grass is used as a breeding ground for pollinating insects, small mammals and birds," explains Jean-Pierre Lagneau, head gardener at Truffaut. The wildflowers that develop there feed insects usefulto the garden. These flowers have a key role in pollination, in the multiplication of fruits and vegetables." When we pass the mower, we destroy everything that lives in this ecosystem. The absence of mowing therefore preserves the biodiversity of your garden.
By no longer mowing, you can get a beautiful carpet of daisies, clovers, dandelions or poppies, depending on the nature of your soil and your region. These flowering meadows attract more pollinating insects, rodents such as shrews, hedgehogs, lizards, birds (goldfinch, robin, chickadee), and all play an important role in the garden. The chickadees, for example, will harvest the small caterpillars on the leaves of the roses, to give them to their young. They also reduce the number of aphids.
Leaving the lawn on the prairie attracts pollinating insects. Miriam Doerr & Martin Frommherz
There is also a correlation between soil, lawn and outdoor wildlife: wild birds with their droppings enrich the soil, making the earth more alive. "Microfauna is transforming everything and life is attracting more and more of them. It is an abundance. The soil is also regenerating," explains Jean-Pierre Lagneau, gardener.
Did you know?
May is the month of peak flowering of melliferous plants, orchidaceae. When we mow the lawn at this time, we prevent access to the nectar to pollinating insects (bees, bumblebees, butterflies...). This causes a lack of resources that directly harms their reproductive success. This is why, in recent years, a British association, Plantlife, has been calling not to mow the lawn in May.
The flowers, if their life cycle is complete, make their seeds that fall back on the ground and reseed themselves. "Flowering lawnsalso allow the reappearance of wilder plants that had disappeared, such as wild orchids, thistles, sweet peas," says Jean-Pierre Lagneau, who recalls that "it is important because the garden is more "resilient". There is no need to put pesticides. Predatory insects but also birds will attack insect pests.
»Other benefits of not mowing
- Keeping the soil cool
Letting the herbs grow keeps the soil fresh. Herbaceous plants capture the sun with photosynthesis and thus regulate the temperature of the ecosystem. Without plants, energy warms the soil, which dries out quickly.
Grass, by promoting moisture retention, limits the evaporation of water present in the soil. The soil does not crack, does not crack. Conversely, a lawn cut dry out faster and turns yellow in case of drought.
Read alsoGarden: 9 tips from pros to renovate your lawn
- Carbon sinks
An unmowed lawn is a carbon sink, at a time when the IPCC in its latest report recommends developing carbon capture. Indeed, plants capture CO2, transform it and store it in the organic matter of the plant through photosynthesis.
Note: when we pass the mower, the products of the mowing decompose and release CO2, which returns to the atmosphere.
40% of insect species in decline
Vincent Lecomte, associate professor of natural sciences at the University of Burgundy, recalls "that according to recent studies, around 40% of insect species are currently in decline and 30% are threatened with extinction in the northern hemisphere. Scientists consider that there is an extinction of insects unprecedented in the history of humanity. Beekeepers are seeing this with thousands of bee colonies disappearing every year in France."
What is differentiated mowing?
For many of us, it seems inconceivable to let the garden become "a wasteland". But it is possible to do a differentiated mowing, also called "reasoned mowing". Of course, stopping mowing means reviewing our relationship with the lawn, no longer trying to have an impeccable grass like a golf green. Vincent Lecomte, associate professor of natural sciences at the University of Burgundy, invites us to change the paradigm: "We must accept nature as it is, abundant, irregular and not want to change it. A wasteland or a herbaceous meadow is wilderness."
Differentiated mowing, also called "reasoned mowing", consists of letting the lawn grow on certain plots, connected to each other, and mowing the places you frequent most in the garden: the place where your deck chairs are installed, the path to the vegetable garden etc. This new practice reduces the frequency of mowing to once or twice a year.
You can leave tall grass next to fruit trees, for example, to help pollination, and mow only at harvest time. Care must also be taken not to mow around important plants, melliferous plants.
The "ecological corridors" between the plots should not be mowed: they allow fauna and flora to circulate easily.
Differentiated mowing makes it possible to make islands, mowing by zoning. EgorovIqor
Jean-Pierre Lagneau, head gardener at Truffaut, recommends mowing a small square near the living room to sit there for napping, as well as where children play and letting the grass rise on the rest of your garden.
Mow at the end of summer, at the end of August if the drought has damaged everything, or in September if the weather is mild. He advises leaving the grass mowed on the ground to feed it during the fall. This will allow the decomposition of plants and give food to microfauna and feed plants. "It's a virtuous circle," he concludes.
If you have a small garden you can mow for example in front of the house and let the grass rise in meadow behind your home.
Good to know
Do not operate the robotic lawn mower at night, as it may destroy the nests of hedgehogs for example and injure them.
You can create traffic lanes with the mower and change drawings from one year to the next. For example, trace paths to the end of the garden, or to the compost, to the vegetable garden or a pond, etc. The paths can be a walk. Jean-Pierre Lagneau advises to put the mower in the high position and mow at about 7 cm. And recommends selecting the mulching function in order to use the waste from the mowing for mulching trees, beds, vegetable garden.
Be careful, however, not to let brambles and woody plants thrive, as this would form coppice that is difficult to regulate.
Playing with these tall grass spaces can be a real delight for fans of English gardens! "It's very pretty. It is a new aesthetic, a country garden. The effect is very interesting," says Jean-Pierre Lagneau.
Did you know?
It is necessary to mow by the middle to allow animals, insects, to save themselves more easily by passing through the sides of the field. This method destroys microfauna less.
How do you compensate if you keep mowing?
- Planting a country hedge
You can plant a country hedge, with evergreen species, which serve as a breeze (such as laurel, Mexican orange tree – which can reach 2 m in height -, Elaeagnus x ebbingei), and deciduous species. They will be chosen according to the nature of your soil, the exposure of the land and the region in which you live.
For a country hedge, Jean-Pierre Lagneau offers photinia (free shrub with its pretty red leaves in spring) or rosehips, lilacs. This hedge will play an important role with pollinating insects and will also host bird nests.
Warning: do not trim the hedge from March 15 to September 15, due to the nesting of birds. Pruning is done in the fall. "It is useless to trim a country hedge with a cord, says the gardener, it must be allowed to develop quietly."
Good to know
A hedge composed of the same species has a big disadvantage: if a disease attacks a tree, the whole row will be sick and destroyed.
- Install a pond
Creating a small pond or pond in your garden is a good option, because it is an ecosystem very rich in biodiversity (plants, amphibians, dragonflies, aquatic insects ...)
- Create groves
They play the same role as country hedges.
- Install "insect hotels"
Setting up an "insect hotel" in your garden provides pollinating insects with a protected place to lodge and reproduce.
- Install compost
By creating compost at the bottom of the garden, you create a small ecosystem.
- Install hives
- Stop using herbicides
The absence of mowing or differentiated mowing make it possible to protect biodiversity in the garden, save time, do without fertilizers and weed killers, save water, regenerate the land. Jean-Pierre Lagneau sums up the importance of this new practice by taking up the formula of Alain Canet, agronomist and agroforester: "Bare soil is damn soil, covered soil is prosperous soil".