Book Review: What A Plant Knows, by Daniel Chamovitz
If you enjoyed Peter Wohlebben’s The Hidden Life of Trees, as I did, then you will find much to appreciate in What A Plant Knows, by Daniel Chamovitz. Chamovitz, Director of the Manna Center for Plant Biosciences at Tel Aviv University, presents an explanation of
the scientific evidence regarding plants’ abilities to see, smell, feel, hear, remember, and understand where they are.
Plants do not experience these senses as we do. They don’t have eyes or brains; so they cannot see by creating mental pictures the way animals can. However, plants do have photoreceptors very much like the ones people have in the back of their retinas. In plants, these photoreceptors can be found in growing tips and in leaves.
Plants do not grow toward the light because of photosynthesis, they do so because the photoreceptors in the growing tip sense the light. If you cut off the tip, the plant will no longer move toward sunshine. Plants detect different kinds of light and respond to them in different ways. They can also measure the amount of light they are exposed to.
One of the really interesting things is the similarity in how the senses work at the cellular level in both plants and animals. Chamovitz explains that these similarities derive from a shared genetic heritage that goes back millennia to a time before organisms evolved into the plant and animal kingdoms.
For instance, the lobes of a Venus Flytrap close because an electrical current is generated when a potential prey touches two of the inner filaments – a process very similar to muscle contraction in an animal. An animal brushing past or an insect chewing on a leaf – all generate an electrical response in plants at the cellular level.
The ability to hear is one sense that plants lack. In fact, plants possess some of the genes that are associated with deafness in humans. Chamovitz reviews some of the studies purporting to show otherwise (including some claiming to show that classical music is good for plants, while rock and roll is harmful) and finds them flawed. So don’t bother with that outdoor sound system, unless it’s for your own enjoyment.
The author closes with a discussion of whether plants can be considered intelligent. He argues that the question is not very useful. Plants are more like us than we generally imagine, but they are not just like us. Scientists and gardeners alike imagine that their plants are happy or sad (I certainly do). The relationship, however, is entirely one-sided. Chamovitz argues that plants have a complex sort of awareness, qualitatively different from that of an animal, but remarkable all the same.
gardeninacity 
AWESOME post and very interesting… Plants in cultivation definitely respond differently than plants in the wild, too. Maybe the plants in flower beds and pots depend on us for care, and thus respond in kind, by giving us a sense of accomplishment as they thrive.
Right, I think there’s a book that argues that it’s plants that have domesticated people.
Sure sounds like that somestimes. One reason i don’t go anywhere is because of the plants, cows and chickens. GEEZ! I always say they aren’t mine, I am just their caretaker.
Fascinating. I always feel like a cold-hearted killer when I thin seedlings. Soon I won’t be able veggies without feeling a tickle of guilt.
When I thin seedlings Judy calls it “the massacre of the innocents”.
How interesting. I always talk to my plants. Perhaps they feel the vibrations rather than ‘hear’.
It’s possible. In one experiment they thought plants were responding to sound, but it turns out they were stimulated by the heat from the speakers.
I often think about the way plants communicate when attacked by aphids for example, sending chemical signals that alarm nearby plants to produce bitter tasting leaves or nearby ant colonies to march in! I find it all so fascinating and loved this book too.
You’re right, plant communication is really fascinating.
I do think plants are far more complex than most people think. I worry if I know to much more about them then I will not be able to eat them. I do say thank you before I do!
That seems to cover all the bases.
Intriguing! I talk to and “baby” my plants at times. Wonder if it benefits them.
I think we all do that at times. It can’t hurt.
It’s on my list.
I think you would like it.
Goodness, I’m most upset…time to stop talking to my plants? Maybe they get a feel good vibe…xxx
You can still talk to them … can’t do any harm.
I’m not sure how I feel about this – I’m leaning towards guilty since I not only grow & baby them, but also cut them up and eat them.
I’ll bet plants would eat us if they had the chance, so I return to feel guilty about it.
Very interesting and shows how well they have adapted and survived over time (in their own way). I love learning about plants as I spend so much time with them. Thanks for breaking down this scientific information.
You’re welcome.
When I received my first plumeria cuttings — three of them, about 18″ long — the woman who passed them on said, “Just put them somewhere cool, dry, and dark. They’ll let you know when to pot them.” I wondered how they could do that, until I happened to look at them one day in March and found leaves unfurling on the ends of the cuttings — under the bed. I pulled them out, put them in dirt, and away we went.
The business of plants sensing the light makes sense of that experience. That would have been about the equinox — the right time for things here to begin getting ready for a new season of growth.
Maybe the plants are really smarter than we are.
Hello Jason, just your summary is quite eye-opening. What would be really interesting (and somewhat creepy) is to figure out how to make a plant’s needs (e.g. water, light, heat, nutrients) more visible and distinguishable to the humans that look after them – beyond the usual, wilting and dying response, which isn’t always helpful.
Ah yes, if only plants could talk!