19-10-2023 Show

Carré des Jardiniers 2023: “Roof gardens are the future of our cities”, by Matthieu Carla

Landscape architect Matthieu Carla suggests that cities can grow the green lungs they so desperately need with his “Roof Garden”.


Vertically built green spaces make the most of what already exists in cities without contributing to the urban sprawl. But the technical nature of such installations impose new solutions. Landscape architect Matthieu Carla suggests that cities can grow the green lungs they so desperately need with his “Roof Garden”. This is an original solution to the Carré des Jardiniers 2023 theme: “Biodiver'city: How shall we live in tomorrow’s towns?”. While we wait to meet the next Master Gardener in the competition, take a look at his vertical project.


Jardin de Matthieu Carla
Matthieu Carla's garden for Carré des Jardiniers 203


Can you tell us a bit about your background as a landscape architect?

Matthieu Carla: While I was studying for an advanced vocational training certificate in Livestock Production, I was also a community services voucher-based worker, doing minor garden maintenance for clients. In 2009, my customers asked me to clear away the trees that had fallen during a heavy storm. They needed invoices to make insurance claims, so that is how I started my landscaping business. It got so big that I hardly ever went to classes anymore.


In the end, I dropped out of the training program and took advantage of my agricultural background to set up my own business.


Matthieu Carla's Chinese portrait

Each garden is a glimpse of the landscape architect’s personality.

  • If I were a word, I would be... “determination”.
  • If I were a sound, I would be... “silence”.
  • If I were an emotion, I would be... "joy".
  • If I were a type of music, I would be... “jazz or blues”.
  • If I were a dish, I would be... “Toulouse cassoulet”
  • If I were an hour of the day, I would be... “5:30 am”.
  • If I were a superpower, I would ... “unite people for common causes, but preserve each person's individuality”.
Portrait de Matthieu Carla

How did you come up with the idea for your "Roof Garden"?

Matthieu Carla: I always start with what is needed. We were a bit out of our depth with the theme of this year's Carré des Jardiniers, but it's a popular subject. How can we solve the problems of small and large cities? I suggest building vertically on what already exists, “building on the city”, rather than constantly waterproofing.


Hanging plants often do not age well. Landscapers are at the end of the chain, but to create something sustainable, they should be included from the beginning. It is important to bear in mind that plants must be replaced every 10-20 years to avoid damage caused by rooting. Places should also be provided for cranes and new concrete maintenance practices should be developed.


The different stories will only be suggested in our urban roof garden because of the technical constraints of the Eurexpo exhibition hall, but our message is that roof gardens are the future of our cities. We build on housetops, add stories, and create plant columns and cool spots at the foot of buildings...

What is your approach to biodiversity?

Matthieu Carla: I think the way back to biodiversity is through permeable soil: bands of bricks, wood, recycled materials such as walnut shells or peach stones... These types of soil are cooler than tar and allow us to preserve a little wildness and at the same time keep nature in check. Let’s not forget that we're in the city. If we were to mow twice or three times a year instead of regularly, we would save a lot of time (and money).


Do you find it difficult to convince your customers to biodiversify their gardens?


How do you integrate current garden trends into your designs?


Matthieu Carla: As far as design goes, we will have three symbolic terraces: one in a Provençal style, one that is quite dry with graphic plants and a Hispanic atmosphere, and a third that's a bit bohemian with wicker furniture under a pergola, in turquoise and yellow colors.

We're also eager to showcase the versatility of CLT (Cross Laminated Timber) to easily create equipment rooms, pool houses, garden sheds and more. This is a 100% French material created by Piveteaubois, which can even be used to create an entire wooden building. More people should know about this product because it is ideally suited to today's ecological challenges and our needs as landscape architects.

How would you like the professionals who visit your urban garden to feel?


Matthieu Carla: I want people to feel good, to feel cocooned. I like to create small spaces that create a sense of well-being. This garden has to arouse curiosity and make people wonder how it was made, for example, when you walk on slightly unstable ground or on a border made of peach stones.


I think a good landscape architect knows how to take something that seems run-of-the-mill at first glance, like a rickety wooden pallet forgotten at the back of a shed and turn it into something that stands out.

Can you introduce us to your team behind the Carré des Jardiniers competition?


Matthieu Carla: My wife Charlotte Carla and I have been working together since the beginning. We also have 6 employees behind us, and part of this garden was created with the help of students from the agricultural high school in Toulouse (France). I train them, and now they know how to lay out a garden, bond bricks, and so on.


My garden is designed entirely by stakeholders in the local economy, and even a top Toulouse caterer, Esprit Pergo, is participating by donating glass bottles. Together, we can transform many products from their original use into garden landscaping products!


Would you like to stroll through Matthieu Carla's urban garden and discover the various ways he brings more biodiversity to the city? Visit us at Paysalia, 5 to 7 December 2023.


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