How intelligent are plants?
There is a debate raging in botanist circles about how intelligent are plants. On the one side are the practitioners of “plant neurobiology” who claim that plants have a “brain-like command centres” in their root tips, and possess the equivalent of animal nervous systems” (Source Group of biologists tries to bury the idea that plants are conscious) on the other the more traditionalist school of botanists who recently published a paper in Trends in Plant Science, Plants Neither Possess nor Require Consciousness they argue “There is no evidence that plants require, and thus have evolved, energy-expensive mental faculties, such as consciousness, feelings, and intentionality, to survive or to reproduce.”.
It is a complex debate, wandering off into philosophical discussions about what is, and what is not consciousness, present debates about the nature of, well, nature, as well as science. What is certain is that the debate will rage and rage. Botany is the new frontier, there has been some amazing discoveries in the late 20th and early 21st century about the nature and properties of plants, the way they react and the way they interact with each other and the environment around them. Big Pharma spent the back end of the 20th century throwing every combination of molecules together to see what happens, in the beginning it produced results but that road is pretty much exhausted and now they are turning their eyes, and research money towards the world of plants.
I for one do not have either the knowledge or the intelligence to have an informed opinion on the finer details of this debate, what I do know is that plants are pretty amazing and puzzling things. The more I work with plants the less I feel I know. Not in the way that I am getting dumber, although as I get older I am sure what limited brain I have is getting smaller and more sluggish. But in the way that as I work with plants I have more questions that I do not know the answer to, why does a lavender tip cutting planted in early Spring sprout roots but not a salvia elegans, why does one batch of Greek Basil seeds go yellow when another, sown at the same time and put next to it not?
What I do know is that plants are influenced by a wide range of factors, light, temperature, humidity, wind, soil, the slightest change in one of them can lead to dramatically different results.Some of these a gardener can control, other are in the hands of Gaia and we must adapt our approach for a successful result. Though of course my idea of success and a plants may be different, a basil’s “objective” maybe to grow, produce seeds for the next generation and then fade away, whereas mine is to maximise it’s leaf growth, and extend it’s productive life as long as possible so that I can be eating my tomato salads with olive oil and basil late into Autumn.
In a snappily title paper,Cryptochromes Interact Directly with PIFs to Control Plant Growth in Limiting Blue Light the authors write, “Plants are incapable of long-distance migration and therefore must respond appropriately to ever-changing environmental challenges. Numerous environmental factors influence plant development, including temperature, light, touch, water, and gravity. Plants use this information to determine the time of day and season, to assess and anticipate temporal fluctuations in resource availability, and to determine whether they will soon be in the shade of another plant”. The authors in this paper are looking at the way sun loving plants detect and adapt to light and shade, and equally to their neighbours if they threaten to cut off the plants access to light.
While this may seem a tad esoteric for us common and garden plant growers, it actually has very real implications. Plants need their space to grow, if plants are too close together they rapidly become leggy as they literally reach for the sky. Equally however if you want plants to climb rapidly, say for tomatoes and cucumber, tight spacing wll help you achieve this objective. But you have to take into consideration that tight spacing limits the plants root base, it’s ability to find water and nutrients, so your watering and feeding regimes have to adapt appropriately to compensate.
As science has already proven plant genomes are larger than vertebrates, as the above paper clearly states plants are incapable of migration, they have to deal with whatever environmental factors throw at them in place, there is no nipping in doors and lighting a fire for rosemary.
I find plants can deal with the most diverse range of climatic conditions, heat, cold, wind, drought. However what they cannot deal with is rapid change. This year we are a good month behind, not because the Winter was too long, and the Spring late to arrive. Quite the inverse really, we had one of the mildest January’s on record. yes it did get colder in March, but not catastrophically so. What has slowed everything down is the rapid change in temperature during the day, going from 22C in the afternoon to near freezing at night. Plants can adapt but they adapt slowly.
All of which brings us back to the whether plants are intelligent. My gut feeling is that plants are incredibly complex things, able to deal with a lot more variables than we previously thought. But they are incapable of rapid adaption, and it is that ability to react at speed which denotes “intelligence”, so loathed as I am to admit it I tend to side with the traditional botanists on this question.
