Smarty Plants by Ian He

Smarty Plants

Let’s say you have a tree in your front yard. In that same yard, you also have a water pipe buried underneath your yard. And it just so happens that the tree roots will creep slowly towards the pipe, no matter if it is right above it or tens of feet away. Those roots will begin to crush the pipe and crack it. As if the plants know where the pipes are.


Monica Gagliano, an ecologist, tested this by conducting an experiment by putting plants in pots that allowed their roots to only grow in two directions- one with no water, and one with a water pipe. Most of the plants were shown to grow their roots in the direction of the pipe. The water pipe was also on the outside of the pot, eliminating the possibility of condensation forming on the outside of the pipe.


Gagliano conducted a second experiment, with new factors added. A new pot had mp3 players connected to it: one played the sound of running water, and the other played nothing. Again, there were only two directions the roots could grow. Results showed that most of the roots went towards the sound of water.


Jennifer Frazer, an acclaimed science writer, claims that little hairs at the ends of roots could allow plants to pick up vibrations and “hear”. But this leads to another problem- how does the plant process this information without a brain? And with this same notion, how do plants grow towards sunlight despite not being able to see?





The Mimosa pudica, aka Shameplant, is known for curling its leaves against its stem when touched or shaken, which defends them against predators as a hiding mechanism. Gagliano constructed another contraption that straps the plant to a box. She uses this to drop the plant, from seven to eight inches. Initially, the plant closed its leaves with every drop, but curiously, it stopped curling its leaves when it was dropped.


This brings up two theories: either the plant had “remembered” the sensation of being dropped and came to the conclusion that the drop was not harmful and therefore it was unnecessary to curl its leaves, or that it became tired and ran out of energy.


This was tested by shaking the plant, when it then closed its leaves, proving that it had not become tired and had indeed remembered the drop.


The team at Radiolab performed a similar experiment, unknowingly adding many inconsistencies and unsurprisingly having the plant curl its leaves every time.


Gagliano began repeating the experiment on the same plants, with various lengths of time in between, and every time, the plants did not curl their leaves.


Pavlov, a famous physiologist, studied if dogs could associate the ringing a bell with meat. This was done by ringing a bell every time they received meat, and eventually, the dogs would begin to drool when the bell was ringed alone.


Gagliano performed a similar experiment with pea plants. She shined a light on them, and then turned on a small fan in the same direction, attempting to condition the plants to this. The plants would lean in the direction of the light. If the fan was blown on the plant with no light, would the plant lean?
The plants did indeed lean towards the fan, expecting the light. Much like Pavlov, the plants associated an unrelated action to food.






Is the anthropomorphism of plants scientifically correct? Should words like “hear” and “see” be applied to plants?





How do you think the plants learn without a brain or nervous system?