Do your plants know what you think?
Can they recognise you?
Do they know when they are to be eaten, attacked by predators, whatâ€™s happening to kindred plants in the vicinity, are they cared for and loved, nurtured and watered?
Can they react to a threat and do they remember things?
Why are there research facilities working on plant neurobiology?
If plants are intelligent, as the latest research is showing, how should we behave toward them armed with this information? Should we adopt a different ethical position if we know they have feelings?
Just as animals are now deemed to have rights, would we need to extend such rights to plants as well?
As gardeners, we already 'tune in to plants', but how do these notions of plant intelligence affect and guide your gardening practices?
Can we 'interact' with plants to improve the yield and nutritional density they provide?
A gardenerâ€™s lot
Notwithstanding unexpected weather events, most factors that contribute to growing an outstanding, productive, edible garden are within the control of the gardener.
Producing exceptional crops is a combination of soil activity (biological activity, soil structure and nutrition), the plants' genetics, timing, water, crop rotations, companion plantings, and now, based on new evidence about plant intelligence, how happy your plants are.
All of these factors can be optimised by the gardener or farmer to produce exceptional crops.
Do plants sense whatâ€™s happening around them?
More than a century ago the Bengali Sir Chandra Bose, did research that indicated plants have the ability to feel, learn and remember. Additionally, itâ€™s been recently proven they can store and recall biological data.
Charles Darwinâ€™s research in conjunction with his son Francis revealed that plant roots could sense light, moisture, gravity, pressure, and other environmental variables and then send the root on its growth trajectory.
The last sentence of Darwinâ€™s 1880 book, â€œThe Power of Movement in Plants,â€ has been received with fervor by todayâ€™s plant researchers: â€œIt is hardly an exaggeration to say that the tip of the radicle . . . having the power of directing the movements of the adjoining parts, acts like the brain of one of the lower animals; the brain being seated within the anterior end of the body, receiving impressions from the sense organs and directing the several movements.â€
We now know that plant roots respond to volume, nitrogen, phosphorus, salt, toxins, microbes and chemical signals from surrounding plants and they will change course if they encounter an environmental variable they â€œconsiderâ€ adverse.
Plant ecologist, Rick Karban says â€œplants perceive competitors and grow away from themâ€.
Of course, this research is causing consternation amongst biologists as it steps well outside of the current paradigm of what a plant is and how it thrives in its environment.
Plants responding to threats
The proponents note that animals have the ability to exercise the choice of either fight or flight as a response to a threat. In rooted plants, the only response available is to fight. It is fixed spatially and has therefore developed an arsenal of responses to survive the threats that come its way and they appear sophisticated in the extreme.
According to Dr J. C. Cahill, all plants have elaborate behaviours above and below ground. In fact, 80% of plant activity occurs below ground. Dr Cahill outlines the responses of the wild tobacco plant where when attacked by the caterpillar of the hawk moth, it releases volatiles that attract the predator of the plantâ€™s predator. Plants release volatiles through leaves and roots that act as both a signal and in other circumstances as a chemical warfare weapon against plant competitors.
This is an exciting time for plant ecologists as they discover the intricate, complex relationships existing between plants, predators and their predators.
Plant roots act like the human brain
Using sensitive instrument, Italian researcher Steffano Mancuso has investigated some of Charles Darwin's observations and discovered that the transition zone of a plant root tip has electrical activity and oxygen consumption with patterns similar to that of a human brain. He goes on to posit the similarity of a rye plant's root zone to being like the internet which is a brain-like system. According to Mancuso, plants have networked intelligence!
In the resource video by Mancuso at the end of this article, you can see images of a plant root that is searching and acting like a worm or a snake would. It's behaviour is complex, sensing and reactive to its environment just as one would expect from an animal with a brain.
Plant root zones:
Mancuso has also done some fascinating experiments where it appears plants can â€œhear the soundâ€ of running water in an underground pipe where the exterior of the pipe is dry. Plants grow toward the pipe in response to the sound of running water.
In humans, our endocrine system produces the brain stimulating chemicals of serotonin, dopamine and glutamate. Did you know that these very same compounds are found in plants?
The Secret Life of Plants
In the 1973 best seller The Secret Life of Plants, authors Peter Tompkins and Christopher Bird wrote about the experimental work of a former CIA operative Cleve Backster who in 1966, attached a plant to a galvanometer. Backster found by simply imagining he was going to do harm to the plant, it produced an elevated electrical response, indicating it felt stress. Backster then worked with collaborators and hooked up all kinds of plants to a polygraph which provided evidence that the plants could read his mind.
Backster also did an experiment where a plant was stomped on and the individual who perpetrated the act was correctly identified when brought before the plant indicated by a surge in plant electrical activity.
Although scientists shunned the plant experiments and findings back in the early '70's, they are now being revisited and plant life re-evaluated as we learn more about the secret inner life of the plants around us.
Plants more evolved than humans?
Scientists have believed that the more evolved an organism is, the greater the number of genes in the organismâ€™s genome. Professor Francis Halle challenged this when he compared the human genome of 26,000 genes with rice which has 50,000 genes and speculated that perhaps plants are more evolved than humans. Plants can recognise their kin and they strive to co-exist rather than compete, so perhaps they are further along the evolutional journey than humans!
There can be no doubt that recent scientific research indicates a need for a re-assessment of plants in the natural order of things. Their response mechanisms are being exposed as complex, sophisticated and adaptive to their environment. In humans, these stimuli are mediated by our brain according to modern science, and yet plants seem to function without one.
If a fundamental criterion for understanding intelligence is the ability to perceive oneâ€™s environment, are plants exhibiting intelligent behaviour?
What does this mean for us as we care for our edible gardens
Based on the latest scientific research and evidence, we are compelled to respect and take greater care of the plant kingdom.
If you are growing a food garden, this starts with providing plants with a healthy soil that has balanced mineralisation.
Then you use plant seeds and seedlings that are suited to biological gardening such as heirloom seeds.
You need to be ever so careful when transplanting delicate seedlings, especially since their roots are now known to be complex sensory organs.
When you care for the needs of your plants use natural, organic, cultural practices including companion planting and crop rotation.
Then, avoid using any chemicals, herbicides and pesticides on your plants.
Finally, talk gently to your plants and think positive, empowering and caring thoughts as you go about your gardening...
And if all this seems very strange then do your own research and formulate your own ideas.
We think you'll begin to take more care when interacting with your plants.