Product Type
Application Area
Lighting Effect
Product Type
Application Area
Lighting Effect


Plants, bridges between Earth and Sun

Interview with Stefano Mancuso, botanist and spreader of ideas

Published: 24 Nov 2021
Science and poetry go hand-in-hand in Stefano Mancuso’s work. The metaphors he uses to illustrate the life of plants are simple and evocative, giving the reader and profane listener the impression that the vegetable kingdom is finally giving up its secrets.

Without doubt, this is a deceptive sensation, as Mancuso succeeds in speaking about botany in a way that everyone understands because he is not profane. A professor at the Agriculture, Food, Environment and Forestry department of the University of Florence, Mancuso is a member of the Academy of Georgofili, a founding member of the International Society for Plant Signalling and Behaviour and director of the International Laboratory of Plant Neurobiology. He speaks at conferences and he has written successful books, such as La nazione delle piante, La pianta del mondo and L’incredibile viaggio delle piante (all three published by Laterza).

He has also helped various artists to create installations in Italy and abroad. The most recent of these is Cerimonia (Ceremony). Born from the creativity of Edoardo Tresoldi, and constructed in Bologna, it covers an area of 4600 m2 that had been abandoned for over ten years. The work is a 5.3-metre-high structure, made of wire mesh and other materials and earth from the site. Specifically designed to interact with the area’s biological phenomena, vegetation is now gradually covering the installation and redefining its architectural forms. This interaction of languages is one more way for Mancuso to explore the connection between the worlds of plants and humans. We interviewed him to explore in detail the different levels of his scientific activity.

A video introduction to Cerimonia by Edoardo Tresoldi in collaboration with Stefano Mancuso

In what ways does light affect the life and behaviour of plants?

For plants, light is nutrition. So, we can say that plants eat light. Light is so fundamental that the entire structure of a plant is constructed to receive the highest possible quantity of light or respond to the lack of it to escape from shadow. Through this miraculous reaction called “photosynthesis”, which absorbs light and transforms it into matter, plants become the bond that unites the Earth and Sun. The Sun is the only source of energy in our system, and all the energy in the solar system comes from it. Plants take this unique and prime source of light energy and transform it into chemical energy, which is what we eat. In fact, plants eat light and turn it into food for us and other beings. 
For plants, light is nutrition.
So, we can say that plants eat light.
Common sense tells us that some plants “seek” light, for example, sunflowers or trees in forests. But how can they seek light if they cannot see it?

Plants perceive light perfectly as they are some of the most light-sensitive beings in existence. They have a vision we would call primitive. They can see sketchy forms. They can distinguish full from empty. They can perceive all the various light wavelengths - much better than ourselves - and they can point themselves towards the ones that have the highest energy power.

The modernity of plants: sensitivity and intelligence without a brain,
lecture by Stefano Mancuso at the Science and Philosophy Festival in Foligno (Italy)

Does darkness have a role in the life of plants too?

A plant is a bipartite living being. There is a part that lives above ground – the leaves, flowers and trunks – and seeks the light, and a part that is underground – the roots – that has the same mass as the upper part but hides from the light. Roots are full of photoreceptors, too, but they are used to withdraw from the light. So, in a plant there is black and white, a yin and yang.

Plants have their own circadian rhythm. So what happens when this rhythm is upset?

Just like us, plants have cycles of resting and wakefulness. Today, we are even assessing whether we can speak about plants sleeping, which is extremely complex, because sleep requires a whole series of factors. To be clear, one of the characteristics of sleep is that each species has its own special position. For example, horses sleep standing up, cows on their sides, and ducks put their heads under their wings and so on. The same thing happens in plants. There are species that have one position and species that have another. Some roll up, others lower their leaves while others raise them. And, just like humans, young plants “sleep” more than elderly ones. Then, there is jet lag. If I suddenly change my body rhythm, it takes me a few days to get used to the new one. The same thing happens with plants. If plants are exposed to a new day-night rhythm that is a few hours different to their usual one, it takes them a couple of days to adapt. And again, just like human beings, if you deprive a plant of rest for a long period, it will die.

The Florence Experiment, by Carsten Holler in collaboration with Stefano Mancuso

Had you worked with other artists before Cerimonia?

I have worked with many contemporary artists. The first was Carsten Höller, with whom we created a wonderful installation at Palazzo Strozzi in Florence called The Florence Experiment. It was a huge success, visited by over eighty thousand people, which is incredible for contemporary art. We put a series of huge slides in the courtyard of the palazzo, so that people could slide down them, some of them holding a bean plant, some without a plant and some plants we sent down on their own. Then in the laboratory, we studied what happened with the people and the beans when they slid down on their own or together. It was an extraordinary experience.

After that I worked with Thijs Biersteker, a Dutch artist on an installation at the Cartier Foundation, in Paris, called Nous les Arbres. Then I started the project with Tresoldi.

When Tresoldi came to you for Cerimonia, did he already have a project in mind?

Yes, he had an idea and we discussed it together. Today, it is becoming essential for artists to begin working with scientists. Some of the most prestigious residencies in the world are now awarded to pairs of artists and scientists who create new projects together. I love this kind of process. I am a pure scientist and I have published over 300 scientific articles on the extraordinary life of plants, but they were only ever read by five or six colleagues around the globe who study these things. At a certain point, I got tired of this situation because if science only ever stays in the laboratory, it is no use, whereas art always conveys a message – even if artists often don’t like to talk about it.

Symbiosia by Thijs Biersteker in collaboration with Stefano Mancuso

Let me give you an example. In Carsten Höller’s exhibition, going down these slides holding a plant was an important message that showed that the being in your hands felt the same sensation of fear you did when moving so fast. It also indicated that, just like you, it might prefer to be alone or share the company of others. Many of the 80 thousand people who visited The Florence Experiment, still write to me saying that it changed their view of the plant world completely. Today, I believe that seeing plants is fundamental for the survival of our species, as the question of the environment can only be solved with plants. That’s why I welcome any collaboration, as it gives me the chance to widen my ideas.

In this period are you working on any environmental sustainability experiments or projects?

Apart from my work in the laboratory, what takes most of my time at the moment is trying to get people to understand - and by that, I mean our leaders and any other decision makers - that we need to plant a trillion trees to respond to the problem of global heating. This is obviously not enough to solve the problem, but it would gain us around seventy years which would be very useful. We still do not see what is happening to this planet. It is changing exponentially and there will be catastrophic results if we do not understand that we have to rapidly do something fundamental, like planting these trillion trees.