The Wall’s Gardener

Locked up in my ancient residence in Florence, I try to travel with my imagination. I have always kept the 45 diaries that mark the course of my life as a university teacher. They contain all my work appointments, meetings with people who have left an indelible mark on my life, a detailed description of my frequent travels to many countries around the world, and the life and work experiences that have shaped my cultural identity.

However, being the son of an artist-pianist, who taught me rigour and discipline from a very young age, I have always noted in the pages of these diaries the food for thought that illuminated the moments of pause that I was able to impose on myself during the hectic working days that have constantly characterised my past life.

Putting the world on pause in order to question the meaning of certain cultural encounters or events that change your way of life and your working method. The ability to marvel at phenomena on which we all rarely take the time to reflect was also one of Leonardo Da Vinci’s secrets; who, fortunately for him, did not have the thousands of distractions that we suffer today in the contemporary world.

Randomly flicking through one of these dusty diaries, kept in the old family trunk, which my parents used for their holidays, a photo of the church of St.Sulpice in Paris appears, followed by the words, in capital letters:

Espace Electra, Fondation EDF: “Exhibition Folies Végétales” – Arr.6^ème. For a moment, I am reminded of Isabel Allende who, about a beautiful photograph, says “… a beautiful photograph tells a story, reveals a place, an event, a state of mind, it is more powerful than pages and pages of writing”.

And that’s exactly how it is, because in my imagination, struck by the image, I immediately recall the chance meeting with Patrick Blanc, hair dyed a deep grass green, nails lacquered in the same shade, surrounded by a crowd of admirers, in the cafeteria of Espace Electra, back in November 2006.

I read a hastily written note on one edge of the page, a statement he had made: “I am a naturalist who observes nature and readjusts certain interactions in different contexts, I am not an artist or an architect, I just think I know the world I work in very well”.

This was French botanist Patrick Blanc’s way of introducing himself, already known worldwide for being the initiator of the vertical garden movement. His incredible vision led him to come up with creative and fascinating architectural designs that included vegetation where no one would have imagined: on the façades of buildings or on interior vertical panels.

Patrick Blanc, is an extraordinary character, who devised his vertical garden concept as a second skin of the building, having the roots of the plants extend only on the surface of the vertical structure, leaving the interior wall intact.

Plants and architecture linked in perfect harmony. Despite this, or perhaps because it has achieved this perfect harmony, it has received very little recognition from the academic world in the field of Landscape Architecture. When, a few years later, I met him again in Milan, at a press conference to illustrate the terrace project, an extension of Caffè Trussardi, located on the ground floor and designed by Carlo Ratti, his ambitions had become even more daring. The terrace looked like a glass case with a real hanging garden on the roof.

However, to grasp the “vision” of this botanical-artist, it is necessary to evaluate the list of species, more than 200, used in this project. Euphorbia, meadow geraniums, lavenders, mini-salvias, sedums, hydrangeas, broom, bluebells, fuchsias, carnations and artemisias intertwine with Buddleje davidii and California white poppies, which normal gardeners hardly ever see in flower.

The life experiences of this artist-gardener resemble those of a nineteenth-century “explorer” with an encyclopaedic knowledge of plants, who for years travelled the world as part of numerous scientific expeditions organised by the Centre National de la Recherche Scientifique in Paris, especially in the rainforests of tropical countries.

While still a student at the Faculty of Natural Sciences at the age of 19, during a trip to Thailand, he discovered with intense emotion that plants grow in almost every imaginable place and do not need soil if they only get water and light. He observed plants hanging from cliffs, climbing rock faces or clawing at cave ceilings.

In his book “Le Bonheur d’être plante” (Boringhieri, 2005), which came out a year before the Paris exhibition “Folies Végétales”, Blanc says that he has always been interested in “the theme of Competition in Biodiversity” and for this very reason he “opposes Darwin’s idea, according to which, in Nature, the strongest always has the best chance of survival”.

All his research in the rainforests of many tropical countries has shown that “Soil is nothing more than a mechanical support for plants. But it is not essential. Only water and the many minerals dissolved in it are essential for plants, along with the light and carbon dioxide needed to perform photosynthesis. All biologists know that plants, in their natural habitat, grow well on vertical surfaces, especially when water is available all year round”.

The first patent for a “plant wall”, the French artist-gardener obtained in 1988, during one of the first show-events at the Domaine of Chaumont-sur-Loire, which would later become the world’s most famous international garden festival.

Patrick Blanc explained to the audience that the creation of a successful vegetation wall depended on many factors, but certainly some were always decisive.

The technical process for which he has been granted a patent consists of an acrylic felt which is fixed to a wall. A coarse mesh grid is attached above it. Irrigation pipes are built into the wall, emitting water only a few minutes of each day. The seedlings are then planted in slots cut in the felt. Successful planting depends on the choice of plants, which must be adapted to the location, solar radiation, cardinal direction and climate.

In addition to botanical knowledge, which obviously requires a high degree of specialisation in terms of the ability to choose species adapted to the temperature and location, there is also the ability to know how these plant species interact with each other in order to guarantee the stability of the compositional aspect over time.

In his book, Blanc also states that he “is sensitive to the architecture of the leaves; for this reason, I use plants that have curves and also plants that do not need pruning. To prevent weeds from creeping into walls, I use a very dense mesh planting technique”. On average, the plants chosen by Blanc for outdoor use are small, with a 10/12 cm diameter pot; planting densities are always over 30 plants per square metre, as in the case of the spectacular green wall of the Museum of Arts and Primitive Civilisations on Quai Branly in Paris.

This “living wall” now houses some 150,000 plants of 150 different species – mostly from Europe, North America, China, Japan, Chile and South Africa – to achieve a high level of biodiversity. Blanc avoided using tropical plants which are unsuitable for a north-facing façade in the Paris climate.

Generally speaking, in most of his projects, which now cover all five continents of the planet, Patrick Blanc estimates that a green wall costs less than €1,000 per square metre, excluding the cost of designing the project, which varies according to the complexity of the locations and contexts.

In each of his projects, the French botanist manages to set up real vertical gardens which, without repetitive schemes, offer solutions rich in different botanical species which, like a palette of colours, transform the place where they are placed into a work of art. Blanc’s vertical garden is a refuge for biodiversity and its installation produces a progressive ecological improvement in urban micro-systems.

Moreover, thanks to its thermal insulation effect, the vertical garden is a very efficient “service” in reducing energy consumption in buildings, both in winter and summer. It is also an effective way of cleaning the air, as the roots and all the micro-organisms associated with them act as a large-scale depolluting service.

In Milan, when presenting his project on the terrace of the Caffè Trussardi, he amazed the audience by stating: “In my opinion, Horizontal (green roofs) has no future, while Vertical offers enormous potential: I dream of making plant walls where people least expect them, like in the underground!”.  Today, we can say that Patrick Blanc has been a “precursor” artist of a new dimension of Landscape Architecture.

Many years before architect Stefano Boeri’s invention (“Bosco verticale”, Milan, 2009) and botanist Stefano Mancuso’s “Plant Revolution” (Giunti, 2017), this eclectic French artist-gardener, who now teaches at the University of Jussieu, Paris, has influenced the virtuous encounter between Architecture and Landscape Sciences since the late 1980s.

His first vertical garden project was completed in 1985 at the “Cité de Sciences et de l’Industrie” in Paris, but his idea did not attract much interest in the world of architecture at the time, with the exception of Herzog & de Meuron and Jean Nouvel.

It was only in the mid-1990s that the concept of ‘vertical greenery’ became a topic of discussion among architects and landscape professionals, but it took until 2005 for this artistic landscape invention to reach a wider audience in Europe.

When I met him in Paris, he declared himself to be a happy and optimistic “metropolitan gardener”, even though “mankind is always living in cities, in a context where Nature has no relevance; therefore, the only spaces accessible to vegetation in our cities are the vertical walls, and if these projects are realised, they can provide better comfort and well-being for our cities. I have outlined a path, and if they imitate me it is a good thing: Nature does not require a copyright”.