Microorganisms, known in the cannabis world as microbes, have been around for some 3 billion years, making them the oldest lifeform on the planet. Incredibly diverse, these microscopic organisms play a crucial role in developing, supporting and maintaining life. In fact, without microbes, we wouldn’t be able to breathe or digest food… and plants certainly wouldn’t be able to grow.

While there are millions of microbial species, there are six major types, including fungi, bacteria, and viruses. They tend to withstand extreme conditions – from freezing to boiling temperatures, low oxygen and high salt environments. Often sensitive to change, these miniature ‘creatures’ living in the soil form beneficial relationships with plants that ensure the proper crop development – and cannabis is no different.

To achieve a high cannabinoid content in the trichomes, proper nutrition is crucial. The nutrition of your cannabis plants will largely determine the success of your harvest. If you want a high yield, you must start with productive soil. The health of any growing medium can be measured by the diversity of organisms and beneficial microorganisms that inhabit it. By maintaining that diversity, cannabis growers can achieve a balanced growing medium and create the ideal conditions for healthy, thriving plants.

Types of Beneficial Microbes in Healthy Soil

The two types of beneficial microbes in healthy soil are bacteria and fungi. They work together with the roots in different manners to promote root health and maximize overall plant function and size.

These microorganisms break down macro and micronutrients, thereby increasing their availability to your plants through the production of chelators (small molecules that bind very tightly to metal ions). Several strains of bacteria also work to supply cannabis plants with growth and bloom cofactors, which enhances branching, budding and flowering sites.

A Symbiotic Relationship

Organisms depend on each other for survival. This symbiotic relationship exists within the soil – between microorganisms and plants – and utilized by growers to ensure plants are bursting with vitality.

Unseen to the naked eye, microbes transform organic energy into food for plants – but in a much different way than the conventional food chain (animal eats grass, animal eats animal). Rather, the energy from which the microbes feed is provided through photosynthesis – the plant’s chlorophyll absorbs light, thereby transforming inorganic energy into organic energy.

From there, the combined minerals and CO2 form organic compounds that feed the microbes in your growing medium. After the feast, decomposition begins. The microbes first digest and “exudate” nutrients that are then ready for plant absorption. Continuous microbial activity not only benefits the soil, keeping it loose and nutrient-rich, it also facilitates root development while boosting the bioavailability of nutrients.

Nutrients to Promote Soil Microbes

Soil microbe quality and conditions differ from an indoor crop to an outdoor one. For sun-grown cannabis crops, the soil’s microbial life is more likely to regenerate on its own. Indoors, the grow medium should be encouraged with compounds specially formulated to promote soil microbes.

Mills Nutrients is an ideal option for both indoor and outdoor operations. Created with a highly concentrated bio-mineral base, these nutrients are designed for easy plant absorption to help optimize growth rate, yield, flavor and aroma. Of the complete product line, Mills’ Vitalize formula, in particular, is designed to stimulate the growth of soil microorganisms while working synergistically to promote overall plant health. This formula is especially effective when used in conjunction with beneficial biologics like mycelium and mycorrhizae.

To ensure proper nutrient uptake into your bloom cycle, Mills Ultimate PK is a unique phosphite-based bloom stimulant designed for the last few weeks of flower development. Phosphite is an extremely bioavailable form of phosphate, which works to preserve the life of your soil microbes (unlike regular phosphorous-containing fertilizers that kill your microbiology). Therefore, Mills’ carefully-crafted formula ensures that your soil is living and your cannabis plants receive the proper nutrients late into flowering.

Avoid Pesticide Use to Stimulate Soil Microbes

Pesticides are often used in industrial agriculture and by non-organic cannabis growers as a chemical method for deterring unwanted pests such as whiteflies, aphids and cucumber beetles. While chemical use is enticing to protect your cannabis crop, these formulas are associated with a number of health conditions in humans and can also harm wildlife when they seep into waterways. Aside from killing unwanted pests, chemical pesticides also negatively impact beneficial soil microorganisms, thereby decreasing the countless microbial benefits.


If you have questions or aren’t sure where to start, contact the Garden Rebels team. We offer on-site consulting and will help you set up your grow and troubleshoot issues so that you can maximize your yield and revenue stream.