Zoë Schlanger Interview, plus links to author biography, book summaries, excerpts and reviews

An interview with Zoë Schlanger

A Q&A with the author about her book, The Light Eaters.

Q. What, to you, is THE LIGHT EATERS about?

A. The most interesting part of this book for me is the undercurrent of a question that runs through it: What would change if we began to regard plant life as sentient in its own way? Everything suddenly becomes quite alien. That's what happened for me in  reporting this book: being outside—or at home with my houseplants—became an  encounter with alien life-forms. Once I pulled back the veil on what they were truly  doing, the natures of their idiosyncratic and totally active lifestyles, it became impossible to regard them as passive objects. Plants became subjects, full of desires and cunning strategies. My experience as a human on earth also fundamentally shifted; I began to be able to see myself as part of a system that relies on other organisms— especially plants!—for my continued survival in a very literal, tangible way. It opened me up to a different ethical orientation as well. I had to ask myself how I should move through the world if I know that plants have the capacity to feel, to remember, to count. It's an astounding reorientation, something I'm still working on understanding today.  It's both an urgent and deeply rewarding project, trying to understand that. That version of the world is not just more scientifically accurate, but also much more enchanted. 

Q. You were working as a science and environment reporter when you stumbled into the fascinations of the plant kingdom, which happened to coincide with a pivotal moment in the field of botany. Birders talk about the "spark bird" that got them interested in birding. Was there a "spark plant" for you? What were your earliest questions about plants, how did they map onto this moment, and how did they evolve over the course of writing this book?

A. "Spark plant," I love that. Absolutely. My spark plant was a tiny fern named Azolla filiculoides, or just azolla for short. It's tiny and so bright green it looks lit from within. It's one of the smallest ferns in the world, and it has grown in wet places for millennia. Ferns are some of the most ancient land plants on earth, and they feel like a window into a primeval world. Yet despite being so primitive, they can do amazing things. Azolla, for example, fundamentally changed our climate 50 million years ago, when the world was a much warmer place. The Arctic was tropical and swampy, and the azolla loved it. It grew over the Arctic Ocean in thick mats, and was so prolific that it absorbed an incredible amount of CO2, so much that scientists believe it played a crucial role in cooling off the superheated planet. Some scientists are looking into whether it can help do that again. Azolla does many other remarkable things—like house a species of blue-green algae in a specialized pocket in its body. The algae fixes nitrogen, so the fern uses it as its own personal fertilizer factory. Farmers in China and Vietnam have been grinding azolla  into their fields as fertilizer for centuries. I was amazed at the potential in this tiny plant, and it was the perfect link between climate reporting and botany for me. 

Q. Anthropomorphism is a cardinal sin in plant science. The botanists and experts you interview throughout THE LIGHT EATERS avoid imbuing plants with animal characteristics, sometimes resorting to ridiculously gymnastic sentence constructions in service of the passive voice. But more often than not, they admit to you that the "behaviors" they are documenting are significant, resembling something like consciousness or intelligence. At one point, you write of researcher Tilo Henning, "Either he is fed up with me, or I've worn out the facade of careful reserve expected of professional researchers." Can you talk a little about how you approached these conversations? How did you wear down facades and win over these little admissions? 

A. The key thing in any reporting is to build trust. These scientists were worried about oversimplification, of reducing their complex research to easy human tropes. They don't want people to see plants as little cartoon characters, or tiny Yodas. It's hard to talk about something that's so different from us yet also so familiar in its creaturely abilities, while still preserving that element of difference. Scientists do it by using absurdly antiseptic language. I wasn't going to do that, and they knew it, so they were sometimes nervous about that. So I would explain that I was interested in preserving exactly that tension—to hold the fundamental difference of plants and not try to gloss over it. I also tried to show that I had done my homework. I knew the jargon, the scientific ways of talking about plant function, the various disputes in the field. Once researchers realized I wasn't out to use their work to create a sort of plant fairy tale, they got more comfortable. But not always. Sometimes I just couldn't get past that facade. 

It's important to note that I do use basic words like "learn," "hear," and "see" in relation to plants. Not all the researchers in this book would approve of that. But the truth is that that is what plants are doing, in their own unique way. I think of the Greek philosopher Theophrastus, who recognized that people needed human metaphors to help understand other species. He coined the phrase "heartwood" to describe the core flesh of trees, for example. Language like that is a useful analogy, where the analogue is ourselves.

Q. There are plant phenomena that we can observe, but not yet understand—for instance, we know that plants remember, but since they don't have brains, we don't understand the mechanism by which they store their memories. I love the way your book acknowledges the confines of what we know and makes informed philosophical conjectures. "What if the whole plant is something like a brain?" you ask a plant biologist at one point, and she lights up—it's almost too scandalous to whisper, but she agrees with you. Can you talk about scientific absolutism, and the place of philosophy in plant science? 

A. Science and philosophy have been divorced from one another for a long time; Humboldt and Darwin were of the era of the philosopher-naturalist, of using scientific observations to draw conclusions about meaning and ethics. Now we are in the age of scientific hyperspecialization, where scientists in their training are discouraged from philosophical speculation and confined narrowly to their discipline. This produces wonderfully robust and focused science, but with very little reflection on its moral or ethical implications. The vibe is that philosophy should be left to the philosophers.

One place where this is not such an absolute boundary is in Indigenous science. I was very moved, while reading Braiding Sweetgrass, by Dr. Robin Wall Kimmerer's recounting of being a young scientist and wanting to study why asters and goldenrod bloomed so beautifully together. Blazing yellow goldenrod beside the royal violet asters produced a gorgeous visual dynamic. Her academic adviser decided it was not a scientific-enough question. But, she realized later, it was not an unsuitable question for Indigenous science. In taking seriously the question of beauty, and what it can mean, she was able to figure out that bees, too, were attracted to the beauty of the purple and yellow together. Asters and goldenrod were pollinated at higher rates when growing together than they would be alone. I think that illustrates how science confines itself perhaps overly-much from "philosophical" questions, and sometimes misses the forest for the trees, so to speak. 

Q. THE LIGHT EATERS is great fun to read; it's full of surprising plant facts, humorous day-to-day plant drama, and "incredibly salty plant activity." But underneath everything, there is also the existential drama that human activity has imposed on the plant world. For instance, just as we are beginning to understand how crucial plant communication with other species may be, we are also coming to understand that we may be impeding their efforts. You write, "Just as plant's communication can cross the species divide, so can ours. And we're speaking to them in smog." Has your interest in plants pointed back to and reinvigorated your work as a journalist?

A. Absolutely. The research you're mentioning is about how human-made air pollution is actually preventing effective plant communication, by scrambling plants' messages midair. Climate change is fundamentally a problem of air pollution. The same compounds that warm our atmosphere also harm our health when we breathe them in, so the way that our human health and planetary health are linked has been clear to me for a long time. But what I didn't realize is the extent to which that holds true for all life forms; understanding that plants were also susceptible to air pollution—and in turn how incredibly dependent all other life is on plants, ours included—really crystalized for me how much we all exist as part of a system. Understanding the environmental crisis in those terms feels like being fully awake for the first time. It's not always easy for us to see the system in which we live. Plants really help with that.

Q. In our current agricultural practices, the world uses about two million tons of conventional pesticides to control weeds and bugs each year; meanwhile, pests evolve resistance to pesticides, requiring higher and higher doses, until entirely new formulas must be developed. In the United States alone, you write, "as many as 11,000 farmworkers are fatally poisoned by pesticides each year, and another 385 million are severely poisoned but don't die, to say nothing of the birth defects, breathing disorders, and other long-term health impacts of constant exposure to regular doses of the stuff." Is there hope that we might be able to course correct, assuming we can metabolize an understanding that we are, as you say, "contiguous with our environment"? What are some of the practical applications of the research you describe in THE LIGHT EATERS?

A. Changing the way we farm plants is absolutely one practical outcome of understanding plants' inner worlds. Now that we know that plants in the wild are exquisitely sensitive to touch and sound, we can potentially use those things to prime plants to be more resilient on their own, and need less or no artificial pesticides that are harming both farmworkers and the rest of us all in so many ways. There's a new field of research on how plants hear sound, and how playing certain frequencies for plants could activate plants' immune systems, helping them ward off pests and disease on their own. Or how kin recognition in plants could be harnessed to better grow plants that aren't constantly battling each other for nutrients and light. Plants are very social creatures, and sometimes that sociability could be used for the good of farming. Companion planting—a very old science of placing different companionable species together—could make certain plants more resilient than growing them in vast monocropped fields. There's a world of potential innovation all based on the premise that plants could do much more for themselves if we allowed them to.

Q. On one of your research trips in support of THE LIGHT EATERS, you discovered a Boquila plant mimicking a fern. In writing this book, what was your most surprising discovery? Additionally, you cite a number of open lines of inquiry, studies we need to wait to see how they play out. Which results are you personally the most eager  to see?

A. I'm glad you mentioned the Boquila. The question of how this vine in the southern rainforest of Chile is able to spontaneously mimic the size, shape, color, and even vein pattern of plants it grows next to is definitely something I'd love to get an answer for in my lifetime. Right now, there are two dueling schools of thought about it—one of which says it is proof that plants can see. Vision in plants is an incredibly alluring idea. They do have a whole suite of different photoreceptors in their leaves, more than we have in our eyes. Learning how much plants are able to sense their environment based on incredibly subtle variations in light color and strength was a huge surprise to me. Plants know if they're being shaded by a cloud or a leaf, and if a leaf whether that leaf is theirs or belongs to a relative or to a total stranger. The idea of some sort of vision in plants is not entirely far-fetched. But they don't have eyes, or a brain, so clearly whatever is happening is very different than the version of vision we experience. But this mimicking chameleon vine in Chile really pushes the envelope on that concept. A plant that can mimic another plant's texture? That's on another level.

Q. Humans stand to gain so much from observing how the plant kingdom has evolved parallel to ours—from queering binaries to adopting social intelligence and cooperation to understanding how our environments work on us (including deep connections to the microbial and fungal worlds). Has looking so closely at the plant world changed the way you view the animal world? Are there lessons you would like to see humans apply?

A. I think one striking thing I came to understand was that the divisions between "plant" and "animal" are somewhat arbitrary. They're lines in the sand that humans drew. Taxonomy is like that: it invented labels and categories that have all been so totally fossilized in our minds that we've lost the thread on how blurry those lines can really be. I think of the emerald-green sea slug, which drinks in chloroplasts from algae in the early part of its life and then spends the rest of its time on earth 

Unless otherwise stated, this interview was conducted at the time the book was first published, and is reproduced with permission of the publisher. This interview may not be reproduced or reprinted without permission in writing from the copyright holder.