When I was growing up on our farm in southeastern Pennsylvania, my father always said that if you spent enough time with any animal, you would develop a bond of mutual affection -- or friendship, as it were.
I saw him achieve that, with all sorts of animals: feral cats, geese, chickens, sheep and cows. He, of course, was a keen observer of animal behavior and could read them very well. I've learned to read animals well, too, and it's one of the joys of my life.
But in considering friendships with animals, I never thought of moray eels. And wouldn't you know, on YouTube I watched a video of a woman diver who had made friends with a moray eel. How utterly astonishing. It took her years, but she developed a relationship with a fish. It knows her.
This discovery made me start questioning my assumptions. If one could make friends with an eel, what else? So of course, being a gardener and plant lover -- and one who regularly talks to my plants -- I thought, well, what about plants? Do they, perhaps, know who I am? I started doing some research.
So it looks as though my plants don't really know who I am, but they actually communicate with one another and apparently respond to human voices. They use chemicals to communicate with each other, and with beneficial insects as well.
While they appear to be completely passive, in reality, plants can call for help by emitting a chemical signal when they are under attack -- and that signal calls out to the insect's enemies. Bean plants will release chemicals to keep aphids away -- and call in wasps to take out the aphids. Plants that are near another plant under attack can also activate their own defense mechanisms. This communication can even cross species: If, for example, a sagebrush is damaged by a hornworm caterpillar, neighboring wild tobacco will respond to its distress call and prepare for attack, according to James Cahill in "What Plants Talk About."
Plants will also defend their territories. Knapweed, one of the worst invasives in the western US, releases chemicals through its roots to kill off native grasses. But lupine in the same areas secrete yet another chemical to form a protective barrier against knapweed, and that actually helps to protect the grasses too.
As a gardener, I've always wondered if plants recognize their own species. I've been taught that some plants shouldn't be next to each other, like onions and beans, for example, but do they like being with their siblings? Some research indicates that it is indeed so -- namely, that individual species recognize each other via chemical signals, and that they are more likely to share root space with siblings.
But what about us? Well, the Royal Horticultural Society undertook a month-long study using recorded voices, and researchers discovered that talking to your plants really can make a difference. The researchers attached headphones to tomato plants, using both male and female voices reading from either literary or scientific works. The tomato plants responded best to female voices, growing an average of an inch taller than those listening to a male voice.
The winner? The great-great-granddaughter of Charles Darwin, Sarah Darwin, who read from "On the Origin of Species." Her tomato plants grew two inches taller. Makes you wonder, no?