The not-so-secret life of plants
From the perspective of Western science, plants have long been considered unaware, passive life forms; essentially, rocks that happen to grow.
But there’s something in the air in the world of plant science. New research suggests that plants are aware of the world around them to a far greater extent than previously understood. Plants may be able to sense acoustics, communicate with each other, and make choices… all this without a brain.
These findings are fueling a debate, perhaps even a scientific revolution, which challenges our fundamental definitions of life, intelligence, and consciousness.
Featuring Zoë Schlanger.
Zoë in a Moreton Bay fig tree at the National Tropical Botanical Garden on Kauai. Credit Gloria Dickie.
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LINKS
Zoë Schlanger’s book is called The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth.
“Everything Will Be Vine” is a great podcast episode from Future Ecologies featuring Zoë’s journey into the Chilean rainforest, where researchers are mystified by a once-overlooked vine.
Jagadish Chandra Bose was an Indian scientist who challenged the Western view of plants in the early 20th century. He studied electrical signaling in plants and argued that plants use language. Read about his life and work in Orion.
This is the now famous study by David Rhoades. Rhoades was derided for his “talking trees” theory, and only was proved correct after his death. Here’s an audio story which goes deeper on Rhoades.
Lilach Hadany, the scientist who likened a field of flowers to a “field of ears,” also recently found that plants produce sounds when stressed.
The study which found that plants respond to the sound of caterpillars chewing, a collaboration between Rex Cocroft and Heidi Appel.
The organization of the octopus nervous system is fascinating.
The Angel Oak, a Southern live oak, on Johns Island near Charleston, South Carolina. CC BY 3.0 via travelthewholeword.org.
CREDITS
Outside/In host: Nate Hegyi
Reported, produced, and mixed by Justine Paradis
Edited by Taylor Quimby
Our team also includes Felix Poon and Marina Henke.
NHPR’s Director of Podcasts is Rebecca Lavoie
Special thanks to Rex Cocroft for sharing the recordings of leafhopper mating calls and chewing caterpillars.
Music by Mochas, Hanna Lindgren, Alec Slayne, Sarah the Illstrumentalist, Brendan Moeller, Nul Tiel Records, Blue Dot Sessions, and Chris Zabriskie.
Outside/In is a production of New Hampshire Public Radio.
If you’ve got a question for the Outside/Inbox hotline, give us a call! We’re always looking for rabbit holes to dive down. Leave us a voicemail at: 1-844-GO-OTTER (844-466-8837). Don’t forget to leave a number so we can call you back.
Audio Transcript: The not-so-secret life of plants
Note: Episodes of Outside/In are made as pieces of audio, and some context and nuance may be lost on the page. Transcripts are generated using a combination of speech recognition software and human transcribers, and may contain errors.
Nate Hegyi: Hey Justine.
Justine Paradis: Hey Nate. Question for you.
Nate Hegyi: Yeah.
Justine Paradis: Is there a particular plant in your life, like maybe a houseplant or tree on your block, that you have a particularly close relationship with?
Nate Hegyi: Well, where I live right now is essentially the Great Plains, and there are no trees around, so there are no trees on my block. But we do have a very particualr plant called kochia. And in some circles, it’s considered an ornamental plant. In this household, it’s a friggin weed, and it has been the bane of my existence. So I wouldn't say an individual plant, I would say a gang of plants, enemy team of plants, that no matter what I do continually keep coming back.
Justine Paradis: You’re attributing some personality, some sort of social relationship here.
Nate Hegyi: Yeah, I kind of see them, you know, in West Side Story, walking down the alley? Walking down a driveway, just [snaps fingers].
MUSIC: SAMMBA, Sarah, the Illstrumentalist
Justine Paradis: Do you, and I’m not saying you actually think this, but do you feel in any way that these plants are also in this relationship in the sense that they’re aware of you?
Nate Hegyi: Obviously they’re aware of me when I’m literally pulling them out and killing them, but…
Justine Paradis: Interesting use of the word ‘obviously.’
Nate Hegyi: I guess I’m assuming that they’re conscious.
Justine Paradis: Hmm!
MUSIC: SAMMBA, Sarah, the Illstrumentalist
Justine Paradis: Do you ever think about it as aware, in any way, of your presence?
Nate Hegyi: Obviously they’re aware of me when I’m literally pulling them out and killing them, but…
Justine Paradis: Interesting use of the word obviously.
Nate Hegyi: I guess I’m assuming that they’re conscious.
Justine Paradis: Hmm!
MUSIC SWELL AND FADE
Zoë Schlanger: Well, I'll start by saying part of the reason I even went into this research is because plant scientists are some of the most delightful people to speak to, no matter where they fall in this debate, they… have such a care and feeling for plants that you don’t often see in the general public, or I had not encountered such ferocious awe.
Justine Paradis: This is Zoë Schlanger. She is a climate reporter at Atlantic magazine.
Zoë Schlanger: It's especially charming to experience someone who studies, let's say, ferns, and can think of nothing more rapturous than a fern.
MUSIC: Soaring, Brendon Moeller
Justine Paradis: So your comment about plants being aware of being pulled out? That strikes right to the heart of a fiery debate gripping the world of plant science. Historically, from the perspective of Western science, plants are not self-aware beings. Scientists understood plants to be inert, passive, almost “rocks that happen to grow.” But in recent years, plant scientists are coming up with findings that are challenging those definitions.
Zoë Schlanger: They're asking very provocative questions. Can plants hear in some way? Can they sense light in complex ways, that suggests some form of vision potentially? Can they, uh, sense their neighbors and assess their kin relationships?
Nate Hegyi: Oh no, should I feel bad about pulling those weeds?
Justine Paradis: Right! Is a plant aware when you touch it?
Nate Hegyi: Yeah!
Justine Paradis: What does it mean to feel something? Can a plant make decisions? Are they intelligent?
Zoë Schlanger: It's a fairly small group of botanists who feel incredibly comfortable using those words. A much larger group of botanists are just going about their work quite quietly, but their findings are still pointing in a direction that … frames plants as explosively different than than has ever been framed before.
Nate Hegyi: This is Outside/In. I’m Nate Hegyi, here with our producer Justine Paradis.
Justine Paradis: Reporter Zoë Schlanger spent years talking with researchers for her book, The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth.
Nate Hegyi: Today on the show, we sent Justine to sit down with Zoë… to talk about why these ideas were, arguably, so long in coming. About what we’re learning about plants now. And what it takes for science to change its mind.
MUSIC FADE
Justine Paradis: In 1973, something happened which set the field of plant behavior back decades. A book called The Secret Life of Plants was published. A few years later, the book was adapted into a movie by the same name.
Secret Life of Plants clip: [music] From this beginning will come a world of harmony between mankind and nature. Through the gift of human ingenuity all things are possible. All that we need is a peaceful sky above.
Zoë Schlanger: And it hit the market exactly sort of at the apex of New Age culture. People were very primed to want to think about plants as perhaps like more humanoid organisms than they perhaps actually are. And so this, this book was about half legitimate plant science history, um, reporting on certain findings, and then about half of it was pseudoscience or science that couldn't be reproduced later.
Part of “The Secret Life of Plants” focuses on the lives of plant scientists whose work was overlooked. Scientists like George Washington Carver, a Black scientist for his research on peanuts. And Jagadish Chandra Bose, an Indian botanist in the early 20th century who explored the possibility of electrical signaling in plants.
But “Secret Life of Plants” also highlighted some very dubious experiments, like studies testing whether plants could sense the thoughts and feelings of nearby humans. Or tests playing songs to plants, testing if plants preferred a certain kind of music.
Secret Life of Plants: Plants have been wired into a complex computer. Their change of mood as they react to the crowds of visitors will be converted into musical expression.
Zoë Schlanger: There was, um, a famous chapter, from, about a former CIA agent who was responsible for developing the polygraph test, and he, uh, strapped a polygraph to his house plants and then imagined himself setting them on fire.
Secret Life of Plants: The split second that that imagery of fire entered my mind, the tracing reflecting the changes in the plant just went right off the top of the page.
Zoë Schlanger: He said that the polygraph test sort of went wild, which implied that they were reading his malevolent thoughts. And this these were the chapters that got were really stuck with popular culture. It's, the book is responsible probably for a lot of people thinking plants enjoy classical music as opposed to rock and roll. Um, it's where a lot of talking to your plants comes from.
MUSIC: Zeriba Flats_Alt Synth, Blue Dot Sessions
Zoë describes The Secret Life of Plants as “a beautiful collection of myths” – but it was also wildly popular. Much to the horror of plant scientists, who did not want to be associated with pseudoscience.
Zoë Schlanger: And it really tarnished the field for several decades because… this was, this is a scientist's nightmare that the public receives information that's not fully baked and then takes it, absorbs it as truth.
Funding and research opportunities dried up for decades. Scientists avoided even a whiff of the idea of “plant intelligence” in their proposals. Quote, “According to botanists working at the time, the damage that Secret Life caused to the field cannot be overstated.”
MUSIC FADE
Justine Paradis: I'm thinking about, you know, how did this, the Secret Life of Plants and this moment, impact specific careers and specific scientists? I'm thinking about the example of David Rhoades.
Zoë Schlanger: Sure… David Rhoades was this out-of-the-box thinker in zoology and ecology, and he was working at the University of Washington
On that campus in Seattle, David was studying a forest of Sitka willows and alders. And one season, webworm moth caterpillars were really bad.
Zoë Schlanger: These caterpillars were eating all the leaves, the trees were really suffering. And then he saw the tide suddenly turn, where the caterpillars started dying off and the trees started recovering. And of course he understood as an ecologist, nothing happens in a system without a reason.
So, trees that are being attacked by caterpillars in this way, they do defend themselves. They launch a counterattack, a type of immune response.
Zoë Schlanger: In this case, the trees appeared to de-nutrient-ize, that's not a word, but –
Justine Paradis: [laughs]
Zoë Schlanger: sort of limit the nutrients in their leaves to the extent that the caterpillars started starving.
Justine Paradis: Wow.
Zoë Schlanger: That was how they tried to defend themselves.
MUSIC: Listen to the Forest Weep (melody stem), Hannah Lindgren
This idea that plants were not passive and helpless in the face of this caterpillar attack, but that they could actively defend themselves? That was controversial enough. But this wasn’t even the wildest part of David Rhoades’ theory. He also observed something else.
Zoë Schlanger: In sampling leaves from this forest, though, David Rhoades realized that even trees that were quite far away from the ones that had been attacked by these caterpillars also were doing this to their leaves. And he published this seminal paper in 1983, I believe… where he suggested for the first time that perhaps trees can send airborne signals through the air to warn other trees of this impending attack so that they can prepare themselves.
All the word choice here is up for debate – but this theory suggests that to some degree, trees were communicating with one another. People called it “talking trees” theory. For a lot of people, it was a little too close to The Secret Life of Plants.
Zoë Schlanger: He was so derided when this came out. Uh, he was sort of shouted out in conferences. Um, he was unable to secure more funding. This was considered just too, uh, controversial. People shouted at him to be seen as legitimate.
You could argue that this paper ended his career. Not long after this experience, David Rhoades left science, and he died not long after.
Zoë Schlanger: Of course, now we understand that he was absolutely correct. Unfortunately for him, he he had this, this sad, um, ending where he… He had tried to replicate his findings and he couldn't. And and that shook his confidence enough for him to leave the sciences. We now understand that he was trying to replicate his findings in a different season than his first study was conducted. We now know that chemical signaling in trees is seasonal, that it changes with the seasons. And so it wasn't that his findings were incorrect, which is probably what he died believing, but they were simply, um, conducted at the wrong time. There was another variable that he hadn't realized within a decade, though, it became fairly common knowledge that trees do do this, that they were capable of long distance signaling when under attack.
MUSIC: Of Our Choosing, Blue Dot Sessions
Over the decades, the long shadow of The Secret Life of Plants began to fade. And science marched on too. Scientists gained new understanding of the genome, and of dynamics happening at the molecular level. They developed new techniques, which eventually allowed them to more precisely identify the chemicals like those David Rhoades has hypothesized existed in the air between the trees.
MUSIC FADE
Justine Paradis: Let's walk through some of what scientists are figuring out and asking about plants. And, um, I'd like to start with sound. In 2011, there were two researchers in Missouri. An animal communication expert and a plant research scientist. And they came up with this question. What was that question? And how did they go about answering it?
Zoë Schlanger: Yeah, these two researchers were Rex Cocroft and Heidi Appel, and they met at a conference.… He was studying leafhopper mating calls…
LEAFHOPPER MATING CALLS RECORDING FROM REX COCROFT
He was recording them. And he was explaining to Heidi that all of his recordings that day were terrible because there was interference from the sound of something else… the sound of caterpillars chewing.
CATERPILLAR CHEWING RECORDING FROM REX COCOROFT
Now, Heidi, who studied plant systems and how plants and insects interact, went, ‘Huh? I wonder if the plant is using those sounds.’ So the two of them devised this study where, uh, they used guitar pickups, piezos, tuned to the exact frequency of the sound of a caterpillar chewing… And they found that just the sound of the caterpillar chewing played through these piezos was enough to induce defenses in the plant… And this is one of several findings now in the realm of phytoacoustics, which is such an exciting discipline, that is finding that plants are very alert to the world of acoustics.
MUSIC: Valkar, Blue Dot Sessions
… another paper I really love in this realm is about evening primrose… flowers that are very bowl shaped and grow very low to the ground. Um, a researcher named Lilach Hadany found that when a bee was approaching, the sound of its buzzing was enough to induce the flower to sweeten its nectar by three times within a very short period of time. And she found that the way this worked mechanically is that the bowl shape of the flower functioned very much like a satellite dish, and that the whole thing vibrated at the same frequency as the bee buzzing… And when she plucked off a few petals that ruined that perfect bowl shape, and the plant was no longer able to do that, and she at some point told a newspaper reporter that when she looks at a field of flowers now she sees a field of ears.
The language of science typically is quite careful and precise. The way a lot of us humans casually make associations and come up with metaphors – can be more artistic.
A field of ears is a beautiful notion, it’s so poetic. For me it instantly evokes an image almost straight out of Alice in Wonderland.
Alice: oh, that’s nonsense, flowers can’t talk.
Flowers: But of course we can talk, my dear. If there’s anyone worth talking to. Or about! And we sing too.
But this is where some of the friction is between science and culture.
Justine Paradis: The language here is, um, “alert to acoustics, responding to the field of sound.” Can plants hear?
Zoë Schlanger: Well, it depends how you define hearing. I – plants can sense acoustic vibrations. We can also sense acoustic vibrations.
Justine Paradis: [laughs]
Zoë Schlanger: We have the luxury of this giant brain that translates that into sound. Plants do not have such a thing, and yet they're able to use the information to their benefit. So if we're able to hold that world of difference, that ocean of difference in our mind, when we say that plants can hear, then I'm comfortable saying that they can hear. But if it's just too, too much of a shorthand and we forget that plants are such alien creatures compared to ourselves and evolved so differently from us, then it can become a problem and perhaps we should stick to talking about acoustic vibrations… but I think metaphors are bridges to understanding. And we have only human language. Our language is very limited. So if we're going to begin to understand them, this is this is how we can start.
MUSIC: Follow the Tracks, Mochas
Plants are also aware of being physically touched. They experience this, often, as a form of attack: being cut, chewed on, or bent.
And that triggers a sort of immune response - chemical messengers to warn other plants, or defend themselves.
Zoë was able to see how plants become aware of touch for herself, during a visit to the lab of Simon Gilroy at the University of Wisconsin Madison where they were studying electrical movement in plants. They'd transplanted fluorescent proteins from jellyfish, the proteins that make it glow, into plant leaves.
Zoë Schlanger: And we went into this dark microscope room, and … one of the researchers in his lab handed me a pair of tweezers and told me to pinch the plant that was under the microscope. And I did… and suddenly this green eminence showed up on the screen, attached to the microscope from the place that I was pinching the plant, and it traveled down the midrib of the leaf, down through the vein system, and spread across the whole plant within about two minutes. And so what I was watching there was literally the plant becoming aware of my crushing it with these, with these pinchers.
Some of a scientist’s caution here comes from an awareness of the dangers of anthropomorphizing: about projecting our experience as humans, or as animals, onto a plant – which is something quite different than a human being. So, taking the nervous system – a very animal concept – and applying that to plants is another point of tension inside this debate.
Justine Paradis: How are people responding to the comparison of a nervous system? Like what are the implications of that word and debate?
Zoë Schlanger: Again, it's at this slippery world of what language we choose to use… So I think it's useful here to think about convergent evolution. Many aspects of biology that we think of as very basic evolved many times in different branches of life. For example, flight evolved completely separately in insects and birds and bats, but to very similar effect. A wing is a wing. We can all see that. Eyeballs as well evolved separately many times. Of course, there's a great variety of very weird eyeballs out there, but they all do very similar things. There's this question now bubbling up about whether or not a nervous system can also be something we think of as a product of covergent evolution. Our nervous system is fabulously complex… But what a plant has might serve a very parallel function. It certainly looks quite similar. You think about the branching system of veins on a plant body. Um, it's if it's something that is being used to transmit electrical signals quickly across a body, to integrate an effect… Perhaps that's a nervous system. Perhaps we just can call it a plant nervous system…
Justine Paradis: This makes me think about octopuses, like how we've really only recently, as I understand it, learned how their nervous system is not centralized, but located throughout their body and in their arms and so different from our own. But, um, just another way of being alive. And I'm wondering, um, is a plant like an octopus? This is my, um, my galaxy brain, seems like I'm stoned moment.
Zoë Schlanger: Totally. No, I, this is a great question. So in the sense that plants have this distributed capacity to sense their world, absolutely. They lack neurons. So that is a huge difference. Uh, octopi, octopuses have neurons distributed throughout their arms, which is such a fantastic thing to think about. But plants don't have those. They have this distributed sensing system. And I think it's useful to think about octopuses and also to think about other sort of forms of distributed sensory equipment like you see in, for example, mycelium. People are thinking a lot about fungi right now and how mycelium can spread out, you know, along the soil for huge amounts of area and still have some integrated capacity to make choices as a whole. It's all one organism, and yet it's so distributed and decentralized. And I think that's a really useful vehicle for thinking about the potential for plant intelligence, because if there is intelligence there, it would be a sort of networked intelligence. A system intelligence that is decentralized and yet integrated in the whole and doesn't require something like a brain. There's no brain there.
BREAK
Nate Hegyi: This is Outside/In. I’m Nate Hegyi. Let’s get back to the conversation with Zoë Schlanger, climate reporter for the Atlantic and author of The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth.
MUSIC: Of Our Choosing (darker tones), Blue Dot Sessions
Zoë traces the profound impact that plants have had not only on us, but on planet earth. The first examples of something resembling the plants we know today – came into being a billion-and-a-half years ago. Since then, they have been profoundly successful. Spreading across the globe. Photosynthesizing and producing so much oxygen that they transformed the earth’s atmosphere. One team of researchers estimates they represent 80% of all biomass on the planet.
And yet – we’re still learning what plants actually are.
Our producer Justine Paradis sat down with Zoë to talk about what is happening in this moment in plant science, when new ideas challenge foundational beliefs about plants and what it means to be intelligent.
MUSIC FADE
Justine Paradis: What are the implications, if plants are intelligent, if they could hear or talk to each other or are aware of us – I know I'm using language loosely here, but if all that turns out to be accurate, what does that matter?
Zoë Schlanger: Well… plants will just go on being plants, whatever we decide to think about them. But I think it's really important for human culture to reckon with these things, because for so long, at least in Western culture, plants are have been dismissed as passive organisms that are useful to us. But that's where their individuality ends. And I think understanding plants as agentive and active turns them from objects into subjects in a way that is very important to do. I mean, seeing plants as subjects opens up a realm of respect... It's also produces a tremendous amount of awe in me to understand all these things about plants… and typically awe leads away from exploitation. And I think that there's a lot of repair that could be done in our own relationship to the plant world in terms of recognizing how we are incredibly dependent on them as organisms at this very fundamental level. I mean, plants have produced all of the sugar that has literally made it possible for us to build our bodies, for our brains to run. I mean, everything we do is powered by plants. Even if you've gotten that sugar from another source, let's say from eating an animal… the base of that is a plant that photosynthesized and produced a molecule of glucose. And that's a very humbling experience to fully recognize that.
Justine Paradis: There are also practical implications for things like agriculture, correct? If we understand certain capacities of plants?
Zoë Schlanger: Yeah. There's really interesting implications for agriculture. I am fascinated by the idea that perhaps using plants’ innate ability to defend themselves better could help us do things like use less pesticides. For example, there's some research around using acoustics to prime plants’ immune systems. Um, this is all very preliminary, and it's a very mushy field.
Justine Paradis: Sure.
Zoë Schlanger: But there are papers about this now. And, um, if we know that certain sounds can cause plants to prime their immune systems and, and get alert enough to defend themselves from pests, perhaps that's a way to use fewer pesticides in the long run.
MUSIC: Hitchcock Would Have Fucked Up Charade, Chris Zabriskie
There’s a lot of ways this could look. Playing certain sounds might boost plants’ defenses – often, the compounds the plant is using to defend itself are also the qualities we enjoy, like the aromatic oils in rosemary.
Some plants have the capacity to summon predators to attack marauding pests. the lima bean. When attacked by caterpillars, it can emit an aromatic compound called terpene to parasitic wasps. Recently, researchers bred rice plants with that same terpene from the lima bean to see if that ability might transfer – and in trials, the new breed of rice was able to summon its own pest predators.
MUSIC SWELL AND FADE
Zoë Schlanger: So there's many ways that this, this work could be used to, um, produce our food in a way that could potentially cause less harm to people, you know, um, pesticides and herbicides cause a tremendous amount of poisonings in farm workers each year, and it's a losing game. Plants develop resistance to herbicides, weed plants; insects develop resistance to pesticides. So I think there's a lot to be learned by letting plants do more of the talking, so to speak, for themselves.
Justine Paradis: To go back to the culture of science. Um, I'm curious about this conservatism, um, that science is, in a way, quite resistant to discovery and almost sometimes punishes people who make discoveries. That might be too strong of a word. But what are the what are the benefits and drawbacks of being slow to change your mind within, like a larger culture of science?
Zoë Schlanger: The scientific process and how things are tested and then how they are verified, and then how that work gets published, is a slow system with a tremendous amount of backstops built in. The process of peer review, for example, is perhaps where a lot of, um, dubious science would die before it ever makes it out into the world as a published paper. And that produces slowness and skepticism, but it also produces really rigorous results. And in a world of misinformation now more than ever, extremely crucial and a very good system to prevent quackery from getting out in the world. But like you said, it also resists sometimes discovery… anything new is is controversial. And I spoke to many scientists who had their work received that way the first time they published on it. For example, Susan Dudley, who's a researcher… in Canada who was the first to discover kin recognition in plants in 2007, told me as soon as she realized what she had found, she prepared herself for the pushback. She was confident in the results, and her paper was absolutely solid… and it sparked a whole new field… But for the first couple of years, she was berated or doubted, or there were response papers written as there is whenever there's a new discovery that cast doubt on it. And this is the way the … science pressure tests itself. And I think it's a very good system. But, um, but it has that flip side of sometimes resisting discovery.
Justine Paradis: So some of these ideas that are, you know, revolutionary within the field of science, some of them feel quite intuitive or like folk truths, like, uh, you point out that a plumber wouldn't be surprised to hear that plant roots can hear the sound of running water, for instance. It's like a problem in cities. Plant roots go towards pipes. Um, also, many indigenous worldviews literally treat plants as kin… beings with agency. And I'm, I'm curious… if funding and peer review boards were not centered in a Western worldview, if they were coming out of a different foundation… It's a speculative question, but would we not know some of these things much sooner?
Zoë Schlanger: That's a great question. I think science is one way of knowing things, and it's not the only way, but it is the way we produce a specific type of knowledge. And I'm not sure if – it's, this is a big question. I'm not sure if the actual structure of science could open wide enough to accept other ways of knowing and still be, quote unquote, the form of scientific understanding that we have today. I think there's really interesting movements to integrate, um, traditional knowledge into scientific finding and certainly into scientific pursuits like conservation. And that's wonderful and will bring out new questions. But at the present form of science that we have now, it can it can really only ask the questions its trains, its scientists to be able to ask that sort of fit inside the parameters of the scientific method. And that's a limiting factor. And scientists know that. Um…Yeah, it's a great question.
MUSIC: Listen to the Forest Weep (stems melody), Hanna Lindgren
As I read Zoe’s book, I was constantly in a state of excitement and awe. For a couple weeks there, I”d talk about it to anyone who would listen. In fact, I imagine I was feeling something quite similar to the people back in the 1970s reading The Secret Life of Plants.
If you’re listening and you’re a plant scientist, I don’t mean to make you nervous. These new findings are obviously different.
What I mean is: the idea that plants have the capacity to sense their world, to sense us, far more than I’d previously understood.
Even if you look at all that in the most dispassionate, technical way possible, it just tells me that evolution is amazing. I don’t think you need to wander too far out on a limb, so to speak, to feel a deep sense of wonder.
MUSIC FADE
Justine Paradis: Well, there’s something to plants being magical, quote unquote enough, uh, for what they can really do.
Zoë Schlanger: Exactly. We don't even have to extrapolate too far. We don't even have to really enter the mystical to be completely awed by what plants are capable of. And this is, the scientists I spoke to who prefer not to use terms like plant intelligence, their argument is that plants are so different from us. We don't need to layer on these human notions of intelligence and consciousness that are sort of dirty with lots of human meaning, onto these plants, because they're, they're incredible enough on their own. If we could just learn to respect them as true others, we would do ourselves a great service.
Justine Paradis: I mean, it feels like we don't have definitions for not just intelligence, but consciousness…
Zoë Schlanger: Right.
Justine Paradis: Life. Plant.
Zoë Schlanger: Death!
Justine Paradis: Death!
Zoë Schlanger: Yes, there's a lot of things that that sound like biological concepts, but we simply don't have fixed definitions for. I mean, consciousness is the trickiest one, right? We don't even know the mechanical substrates for consciousness in ourselves. We have no way to completely verify the consciousness, essentially, of anyone but ourselves. We feel it in ourselves. But that's kind of where verification stops. So that is the mushiest of concepts. I have begun to enjoy the word ‘agency’ much more, because that means they're just alert to the world and that they have a stake in their future. They have some say in the direction of their life, and plants absolutely have that. They're constantly reshaping themselves according to environmental fluctuations. They are planning for the future. They are even planning for the future of their offspring. There's a whole realm of maternal care in plants, uh, in terms of their ability to sort of adjust the environment for their babies very literally. Um, so plants are agentive, and I think that does enough to expand our minds to kind of include them in our imaginings of the more vibrant world.
Justine Paradis: Thank you so much, Zoë.
Zoë Schlanger: Wonderful to talk to you.
MUSIC: Nema, Alec Slayne
Nate Hegyi: Zoë Schlanger is a climate reporter for the Atlantic and the author of The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth.
MUSIC SWELL
This episode of Outside/In was produced by Justine Paradis. It was edited by Taylor Quimby. Our team also includes Marina Henke, Felix Poon, and me, Nate Hegyi.
Justine Paradis: Special thanks to Rex Cocroft, for providing the recordings of leafhopper mating calls and caterpillar chewing used in his research with Heidi Appel. Music in this episode came from Mochas, Hanna Lindgren, Alec Slayne, Sarah the Illstrumentalist, Brendan Moeller, Nul Tiel Records, Blue Dot Sessions, and Chris Zabriskie.
Nate Hegyi: Our director of podcasts, the wolf tree in our forest, is Rebecca Lavoie.
Outside/In is a production of NHPR.
CATERPILLAR CHOWING DOWN