Plants are not silent: They communicate with microbes
Many growers primarily think of fertilizer when it comes to nutrient supply. But plants don't simply "passively" absorb nutrients from the soil – they actively communicate with the microbiology in the root zone.
This communication is not a marginal phenomenon, but one of the most important mechanisms that determine how quickly and stably a cannabis plant grows.
Plants send signals, release messenger substances, attract certain microorganisms, and actively repel others. Microbes respond with enzymes, organic acids, and nutrient conversion.
The relationship between cannabis and microbes is a precisely tuned symbiosis that you, as a grower, should understand and foster.
What does "symbiosis" mean between plants and microbes?
In this context, symbiosis means that both sides benefit.
Cannabis offers microorganisms:
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Energy in the form of sugar
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Protection through the root zone
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Stable environment
In return, microorganisms provide the plant with:
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More available nutrients
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Enzymes for root health
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Protection against diseases
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Growth stimulants
This relationship is so close that plants would be only partially functional without microbes.
How plants communicate via root exudates
Communication occurs through so-called root exudates. These are organic compounds that roots deliberately release to attract and control microorganisms.
Exudates include:
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Sugars
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Amino acids
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Peptides
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Vitamins
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Secondary plant compounds
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Organic acids
With these substances, the plant can determine:
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Which microbes are promoted
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Which bacteria are allowed to proliferate
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Which microbes are displaced
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Which processes in the soil should be enhanced
The plant doesn't just feed "blindly"; it steers precisely.
Why cannabis communicates particularly intensely with microbes
Cannabis is a fast-growing plant with a high metabolism and high nutrient demand. To achieve this performance, it needs:
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Rapid nutrient mobilization
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Stable pH values
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Efficient root development
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High stress resistance
All these points can hardly be realized without microbes. That's why cannabis releases more sugar through its roots than many other cultivated plants – a sign of how important microorganisms are for this plant.
How microbes respond to plant signals
As soon as microorganisms perceive the exudates, they begin to work. Bacteria and fungi respond to the plant's signals with:
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Nutrient conversion
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Enzyme production
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Release of organic acids
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Formation of a protective biofilm
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Competitive exclusion of pathogens
These processes ensure that the plant receives the right nutrients at the right moment.
Examples of direct interactions
There are numerous concrete examples of how microbes and plants influence each other.
Example 1: Nitrogen supply
Plants send out signals → nitrogen bacteria increase their activity → more ammonium & nitrate are produced → growth accelerates.
Example 2: Protection against pathogens
A plant under stress releases certain substances → microbes recognize these signals → they form antimicrobial compounds → pathogens are blocked.
Example 3: Phosphorus mobilization
In case of phosphorus deficiency, the plant increases the release of organic acids → phosphorus-solubilizing bacteria react → they release fixed P.
These processes run permanently in the background – without human intervention.
How you, as a grower, can promote this symbiosis
For optimal communication between plants and microbes, an active and stable soil life is needed.
Growers can support this symbiosis through:
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Regular use of fermented microbial products
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Organic fertilization (feeds microbes instead of displacing them)
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Constant moisture
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Low salt stress
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Good oxygen supply in the soil
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Microbially active substrates
The more microbial diversity there is in the soil, the better plant communication works.
What disrupts symbiosis
Communication between plants and microbes can be disrupted if:
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Substrates are sterile
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Fertilizer is used in too high a concentration
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The pH value fluctuates greatly
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Too much chemical cleaning is used in the grow
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Waterlogging occurs
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The soil dries out too much
In such cases, the exchange between the plant and microorganisms breaks down – and growth immediately suffers.
Conclusion – Communication is the key to strong growth
Microorganisms talk to plants – and plants talk back.
This communication controls the entire nutrient supply, regulates the soil environment, and protects the roots from diseases.
Growers who understand and foster this symbiosis cultivate more stable, robust, and high-performing cannabis plants.
In the next article, we explain why soil biology is indispensable for every grower – and how even small changes in soil life can have a big impact on the growth, yield, and health of your plants.
