The root cause of pests and weeds

mothEcosystems are composed of organisms with complementary needs, including light, air, space, water and nutrients.

Every species occupies a slightly different ecological niche, prefers different foods, and in turn contributes different value-added products towards someone else’s food supply.

The greater the biodiversity, the greater the overall fertility of the soil and the chances that all will find exactly what they require for optimal health.

We are what we eat, and the same is true for plants and all the other organisms in the garden. Just like us, plants, animals and microbes cannot thrive without balanced nutrition. We derive our food from the plants, the plants derive their food from the air and the soil.

We like to think that plant feeding insects and microbes - what we call “pests and diseases” - are the cause of our plants’ problems, but they are only the result.

Insects perceive their environment with their antennae. Just like man-made antennae, they are tuned to receive one or more electromagnetic frequencies. For instance, when the female moth’s pheromones attach themselves to the male moth’s antenna, the insect decodes their frequency and interprets it as “mate”.

Plants also emit many volatile substances, and only when a plant’s vibrational frequency enters the range a plant predator (“pest” or “disease organism”) equates with “food”, will it be attracted to and feed on that plant.

And that only happens when a plant is deficient in one or more nutrients. A healthy plant is - for all practical purposes - invisible to its predators.

Killing the “pests” does not change anything, as no amount of pesticides can provide the plant with the nutrients and growing conditions it requires. We can clearly see this in agriculture where year after year ever more potent pesticides are applied because we are forever treating the symptom, not the cause.

The cause of plant disease is poor nutrition and an unhealthy soil ecosystem. The fate of plants is as inseparably entwined with that of the soil as our fate is entwined with theirs. If we want to eat nutritious food we need to take care of the soil, for we too are part of this web of life.

We think we protect our plants by killing the plant-feeding insects and microbes, when in fact they remove only the weak and diseased, and keep plant species strong. Instead we should thank the insects for removing the nutrient deficient plants from our own food supply.

But what about weeds? Weeds are nothing more than plants that are better adapted to the growing conditions our garden provides than the plants we would rather see.

The ability of a plant community to adapt to changing environmental conditions is Nature’s intelligence at work. When one species suffers another takes its place, and the greater the diversity the more resilient the ecosystem is as a whole.

But when our lawn suffers and its helpful companion plants fill in and ensure a continuous food supply for the soil dwelling organisms we call them weeds and kill them. However, no amount of herbicides can provide the grass with the growing conditions and nutrients it requires.

A healthy ecosystem has the resilience to deal with adversity. Populations of individual species fluctuate through drought years and floods, excessive heat and cold, but the great diversity of species allows the community as a whole to retain its overall cohesion.

The loss of biodiversity on our planet is very troubling at this time of global climate change. We need to protect what remains, and to re-establish plants and soil health in the areas already depleted.


We go much deeper into this topic in our online course, which you can discover here:

Organic Master Gardener Online