top of page

The Magic of Mycorrhizae & Cannabis

What is Mycorrhizae?

Mycorrhiza is the singular term used to describe the symbiotic relationship between plant roots and fungi. This relationship begins when threadlike structures known as hyphae penetrate the epidermis of a plant’s roots. The fungi then colonize the roots, dispersing a network of hyphae throughout the entire soil, thereby increasing the absorptive surface area for the plant's intake of nutrients. Although the two best-known classes of mycorrhizal fungus are ectomycorrhizal and mycorrhizal fungi, there are several different classes used to identify them. Additionally, there are more than 150 known species found in different types of climates and soils around the world.

Where do mycorrhizal fungi come from?

The relationship between mycorrhizae and plants can be traced back many years. According to genetic studies, prehistoric ocean-dwelling plants began to slowly migrate onto land many many years ago. They had very minimal root systems, and the soil was tough and unforgiving. Over time, plants partnered up with the fungi that already ruled the land. They evolved together to improve soil: plants developed more complex root systems, nutrient cycles became established, organic matter grew (and decomposed), and terrestrial life as we know it flourished. Modern mycorrhizal products are created at facilities that ‘farm’ or breed select strains of naturally occurring beneficial mycorrhizal fungi. Mushrooms and fungi reproduce by releasing spores. Those spores are then collected, turned into mycorrhizal inoculant products, and sold with the spores in a dormant state. Later, once they’re added to your soil and come in contact with living plant roots and moisture, the spores will germinate and become one with the roots!

How do they work?

A mycorrhizal fungus is a member of a family of complex organisms that are now known to be highly beneficial for plant growth and quality. Typically, most mineral-rich soils will already contain mycorrhizal fungi, however, due to modern issues like overworked soil, tilled fields, and new construction development, most of these soils will often have natural mycorrhizal fungi levels that are far too low to promote proper cultivation. Because mycorrhizal fungi are host-specific, they will only colonize specific plants—meaning that in some soils, the native fungi may not be able to add any benefit to the new crop you have decided to plant. As a rule, it is best to add new mycorrhizal fungi to the soil when planting fresh crops. In the case of soilless cultivation methods, it becomes vitally important to add mycorrhizal fungi manually since these systems are generally devoid of much-needed beneficial organisms. When done correctly, the result is improved nutrient saturation and uptake by plant roots. Mycorrhizae are especially helpful in introducing essential elements like phosphorus, zinc, manganese, copper, and other vital nutrients. In exchange, the plant provides exudates (carbohydrates) to the fungi.

• Promotes larger plant growth and healthier, deeper dark green foliage.

• Leads to greater flower and fruit production (more and/or larger). For farmers, higher yields also mean higher income.

• Enhanced resilience to stress, heat, and other environmental changes.

• Improved water uptake, leading to increased drought resistance and less water demand for the plant.

• Lessens the risk of transplant shock, such as when planting new trees or moving indoor-raised seedlings outside.

• Increases plant disease resistance by promoting overall improved plant health. Also, when plant roots are colonized or coated with mycorrhizal fungi, it limits access to the roots by other harmful pests, fungi, or diseases. For instance, studies show that plant roots colonized by mycorrhizae have added protection against parasitic root-knot nematodes and root-chewing insects!

• Reduces the need for fertilizer inputs (and associated costs).

• Decreases the accumulation and residual levels of toxic contaminants in crops, such as persistent organic pollutants (POPs), which plants typically readily absorb in their roots and tissues.

• Naturally improves soil structure, and fertility, and promotes a healthy living soil food web.

The Power of Mycorrhizal Inoculants on Indoor Cannabis Crops

Mycorrhizae are credited with creating vast underground systems that allow massive tracts of natural growing plants to thrive, so imagine what it can do for your indoor cannabis crop.

For cannabis growers, achieving the best results with the heaviest, most resinous buds is everyone’s goal. Among all the products out there, there is a range of products proven to boost your plants in a multitude of ways but use a natural and organic path that works in harmony with your normal feeding regime to give you bigger, better results. That miracle range of products is from the mycorrhizae family.

Benefits of Mycorrhizae on Cannabis Roots

Mycorrhizae works on the most important part of your cannabis plant — the root system, an area that goes unseen and as a result is often forgotten. Maintaining a healthy root system is an essential part of producing high-quality cannabis. The root system is the foundation from which your plants will grow. Its primary function is to absorb water and nutrients and transfer them to the rest of the plant. The healthier and stronger the root system, the lusher and more vibrant your cannabis will be. Often, we don’t link the symptoms observed on leaves or stalks as being a root problem. Once your root system becomes damaged, it is often mistaken for basic deficiencies, meaning you may never get to the bottom of the problem by adjusting your feed levels alone.

Mycorrhizal products improve your yield and quality naturally and organically. The benefits include improved root growth and health, and an increase in flowering, fruiting, nutrient uptake, water uptake, and final yield.

Mycorrhizae and Cannabis Plants: A Mutual Benefit

Mycorrhizae and plants have a symbiotic relationship where the mycorrhizae fungi and the plant live and work together to mutual advantage. This relationship begins when fungal spores germinate creating threadlike microscopic structures called hyphae. The hyphae enter the plant’s root system, colonize the root zone, and spread out densely into the growing medium, forming an expansive web called the mycelium. The mycelium increases the root area of the plant anywhere between 300 to 800 times, sometimes more. Hyphae are so tiny that they squeeze their way into areas of the soil where normal roots would not be able to reach, making them extremely effective at collecting more nutrients for the plant. The plant feeds the fungi by sending excess sugar it has stored down to the roots, where the mycorrhizae then absorb it to sustain themselves. The mycorrhizae need these sugars because they only exist underground and cannot perform photosynthesis by themselves, meaning the sugars from the plants are what keep them alive. In return for this offering, the mycorrhizae provide the plant with greater access to nutrients, especially those in the form of phosphates. The mycelium increases the root’s area of absorption and helps process nutrient sources into forms that the plant’s roots alone would not be able to access. It increases the take up of all essential nutrient elements but especially elemental phosphorus (P), zinc (Zn), manganese (Mn), copper (Cu), and water.

Mycorrhizae is Perfect for Hydroponic Cannabis

Mycorrhizae products are usually sold in powder or liquid form and most of the top-quality products available are approved for use with organic or synthetic fertilizers in soils, coco, and all hydroponic systems. Mycorrhizae can be used from the very beginning of your growth, at every repotting stage, or even as a top feed. This makes it perfect for cannabis plants as it will support your roots from day one, whether you are growing from seeds or cuttings or just want to maintain a healthy strong mother plant. Although a natural occurrence, mediums commonly used for growing cannabis indoors, including coco coir and those with a base of peat moss or bark, are not composed of and do not naturally contain any mycorrhizal fungi. Therefore, you should add it yourself via a mycorrhizal inoculant. Mycorrhizae do have their tolerances and best-use conditions, performing at optimal levels when the environment is kept between 68-73°F, a pH between 5.5-7.5, and in an environment that has equal air to water ratio. Some species of mycorrhizae can tolerate more alkaline or acidic conditions, however, try to choose a product that contains a blend of various types of mycorrhizae species, as this will make for a healthy mix that works efficiently in a range of varying pH conditions. Hydroponic grow systems are often lauded as producing phenomenal results when it comes to growing cannabis, mainly due to the abundance of water and nutrients that the roots are constantly exposed to, so the use of mycorrhizae here is the perfect fit to enhance results even further. There are mycorrhizal mixes specifically designed for hydroponic systems where spores and hyphae fragments are mixed with delivery media in liquid or powder form. Many generic formulations can be added directly to the hydroponic nutrient delivery, however, as the particles within the mix are small enough to pass through systems without clogging them up. If in any doubt, check the directions before you buy. Mycorrhizal fungi do not generally reproduce in hydroponic systems, so you need to remember to add more inoculant to the nutrient delivery system as the roots develop throughout the life of the plant A hydroponic system needs to be fully aerobic if you intend on using mycorrhizae, so oxygen levels should be maintained at 6-8 ppm via the use of air stones or bubblers, which is something you should be doing anyway to ensure your roots are benefitting from adequate oxygenation. Phosphorus levels of around 70 ppm or more in a hydro system can result in fungal spores going dormant and not germinating, therefore you should carefully monitor phosphorus levels to encourage the presence of mycorrhizae. The presence of chlorine in your water systems can also affect mycorrhizal growth and should be removed from water used in hydroponic applications. The pH of water in hydroponic systems is also important. Most mycorrhizal fungi require a pH range of 5.5-7.0 to survive. Maintaining proper temperatures will maximize mycorrhizal colonization further. Mycorrhizal fungi thrive in temperatures of 65-75°F, which is the ideal range for most plants including cannabis.

Can Mycorrhizae be Harmful to Plants?

There is virtually zero risk of harming plants by using mycorrhizal fungi products in your garden, especially if you follow the application directions provided. Even then, it is difficult to "overdo it". Mycorrhizae do not “burn” your plants as a high-nitrogen product might. If excess beneficial fungi are added to the soil beyond what can form associations with plant roots, they will simply die.

Start Mycorrhizae Early!

The earlier you start using mycorrhizae the better, as fungal spores can take several weeks to establish. By applying from the seed or cutting phase, colonization of your plants will occur quicker via lower dosage levels than if you were to wait until the plant is more mature. You will also see the benefits faster and be rewarded with healthier more fruitful cannabis plants and yields. Most plants grow to their fullest potential when supplied with endomycorrhizal fungi; they produce either more crops per plant, larger vegetables, or more fruits and flowers. This makes mycorrhizae the perfect additive for growing cannabis as large flowering/fruiting plants are exactly what we want. If you are looking for a little extra for your existing grow that is easy to use, provides an abundance of benefits, increases root mass, and is 100 percent organic, then you really can’t go wrong with a mycorrhizal inoculant. It is by far the easiest, most effective, affordable solution to give you a helping hand throughout your cannabis grow cycle.

Our Favorite Mycorrhizal Inoculants

There are a number of mycorrhizal products available on the market. We personally love and use the granular and water-soluble mycorrhizae inoculants from ZEL-TEC. They’re one of the most established and reputable brands, and offer high-quality, effective products that are OMRI and CDFA certified for organic gardening. They add beneficial bacteria to their products to further support the soil food web. Bacteria play a similarly significant role in plant health. In a nutshell, think of them as pre-and probiotics for roots, and roots as the gastrointestinal system of plants. There is a direct link between the human gut, probiotics, and overall improved health outcomes — and plants are no different!


Recent Posts

See All


bottom of page