At the Horticultural Center of the City of Paris, plants and trees to green the capital

2023-04-23 00:11:15

The City of Paris published a report on global warming on Friday, April 21, with temperatures of 50°C expected by the end of the century. Revegetation is one way to make life more sustainable. Visit of the Horticultural Center of Paris, which produces the plants and trees planted in the French capital.

It is in the suburbs that Paris is getting a makeover. In Rungis is the horticultural Center of the City of Paris, 40 hectares of greenhouses and nursery, where grow the plants and trees that vegetate the French capital. “There, the greenhouses are well filled because the delivery periods will start soon, at the beginning of May, for the annuals », shows Fanch Le Garrec, deputy head of the Division. « These are all the plants that will bloom in the flower beds in Paris this summer. »

800,000 annuals, which last only one season, are planted each year. In total, 2 million plants grow here, sown or cuttings. Not to mention the trees and shrubs. We leave the hot and humid greenhouses to find the outside, and a nursery of 30 hectares, at the edge of the motorway, under a high-tension electric line, not very far from the International Market of Rungis, the largest market of products agriculture in the world.

20,000 trees on earth

But in this urban environment, it is already nature, like a young forest, as far as the eye can see. “Paulownia, hornbeams… What’s further on?” Sophoras from Japan, it seems to me,” describes Laurent Chavirac, Plant Purchasing Manager for the City of Paris. « There aren’t all the leaves yet so you can’t recognize everything from a distance… I see Cercis, Judas trees. Some 20,000 trees lined up, 350 different species – pigeons, woodpigeons, magpies and tits have a field day.

Unlike annuals, with flowering plants, with trees long time management prevails. “Ona trees that will spend more than ten years at the Horticultural Center of the City of Paris explains Fanch Le Garrec. “ Ten years is almost two terms of office. Today’s climate issues are paramount. The challenge, on the trees, is really to try to anticipate, to see far away. »

Two million plants each year are produced by the Horticultural Center of the City of Paris. © Florent Guignard / RFI

Plant today with tomorrow in mind

This is how the tree-lined landscapes of Paris evolve over time. “Part of our job is to experiment, to bring species that we know less “, continues Laurent Chavirac . « Is that dit : “Hey, maybe it’s worth trying this species because it looks interesting for tomorrow.” Beech or pedunculate oaks have nevertheless been very, very reduced. On the other hand, the hackberry from Provence, the hornbeam, essences which resist well to dryness, have been increased in volume and planted in Paris. »

But these trees do not grow on their own, they have to be adapted to the city. Long-term work on the trunk, the crown, the branches, “ because there is not always room in a street, because you should not hide the road signs… But the gardeners of the Center horticole de Paris also act in depth, on the roots, so that the final planting of the tree, in the heart of Pairs, is not a failure. ” A tree like this has had 3 or 4 transplants, to work on its roots, to make hair, so that they branch out like a crown when you cut a branch“says Laurent Chavirac. “There are two branches that leave, it’s exactly the same principle to facilitate the recovery of the treewhen it is planted in Paris, to provide shade in the streets and in the Parisian parks.

“Why do the flowers wither? »

Because they are no longer useful. The flower shelters the male and female gametes fertilized involuntarily by the animals, lured by the color of the flowers, their perfume, the pollen and the nectar. And once the work is done, after the seeds are set, the flower no longer has any reason to attract pollinators. The petals wither. It’s like us humans; after the prime of life, we begin to wither.