Are you looking for natural, organic solutions to your garden problems? Whether you’re growing flowers, fruits, vegetables, or cannabis, you can increase yields, resistance to pests and diseases, and overall plant health by applying microorganisms that strengthen plant roots. Sound too good to be true? Mycorrhizal fungi, also known as mycorrhizae, are organic inoculants that make your soil incredibly fertile. Keep reading to learn why every gardener and grower should start using these beneficial fungi.

What is Mycorrhizae?

What is Mycorrhizae?
IMAGE SOURCE: Unknown

Mycorrhizae definition: a fungus which grows in association with the roots of a plant in a symbiotic or mildly pathogenic relationship.

  • Mycorrhizae are natural, organic microorganisms in most soils
  • They bind to plant roots and increase a plant’s ability to absorb water and nutrients from the soil
  • Plants with healthy colonies of these fungi produce large yields, resist disease, and tolerate stress
  • Mycorrhizae act as a living extension of the plant and form a mutually beneficial relationship with it.

Mycorrhizae are a special type of fungus that colonize plant roots and strengthen them. They form symbiotic relationships with most plants on the planet. Plants with healthy mycorrhizae colonies can extract nutrients and water more efficiently than plants without. They are more drought resistant, pest and disease resistant, and typically produce higher yields.

What do Mycorrhizae do for Plants?

These fungi provide amazing benefits for almost all plants. Whether you’re growing flowers, vegetables, or cannabis plants, you’ll see marked improvements shortly after you start adding them to your soil. The treatment works equally well on indoor or outdoor plants, and the effects are cumulative.

Mycorrhizae help plants by:

  • Increasing absorption of nitrogen, phosphorus, and potassium
  • Enhancing the plant’s ability to take in micronutrients
  • Improving water absorption rate
  • Enhancing root growth
  • Delivering nutrients directly to the plant’s nucleus
  • Improving the plant’s tolerance to drought and stress
  • Replenishing soil depleted by repeated plantings and topsoil removal
  • Studies on mycorrhizae fungi have found that plants with healthy colonies of these fungi were less likely to have disease-causing organisms.

Symbiotic Relationship

Most plants have a healthy, symbiotic relationship with these fungi. It’s a mutually beneficial relationship that has lasted millions of years.

So, how does it work? Plants produce carbohydrates that create sugars, which are the main food source for the fungus. The fungus eats the carbohydrates and continues to grow. In return, the fungus creates a network of underground “feeders” that work as extensions of the plant’s roots. These extensions, better known as hyphae, become like a second root system for the plant.

What does that mean for you? It means stronger, healthier plants and bigger yields. Read on to learn how you can create these colonies in your indoor or outdoor plants.

How do Mycorrhizae Colonize Plants?

How do Mycorrhizae Colonize Plants
A microscopic cut of rice root colonized by mycorrhizal fungi.

There are three main ways that these fungi develop on plants: from spores, colonized root fragments or vegetative hyphae. The latter two sources are known as propagules. When you look at the label for a product that has mycorrhizae, propagules are the primary unit of measurement in most products. We’ll get more into spores vs. propagules in just a bit.

Mycorrhizal fungi must first be present in the soil and close to the plant roots. As the plant’s roots grow into the soil, they release fluids that are known as exudates. The nearby fungi sense the presence of these fluids and begin moving toward the roots. Once there, they begin feeding on the exudates and establish a colony.

The root feeds the fungi, and the fungi continue growing with the plant’s root system. The mutually beneficial cycle continues as the mycorrhizae expand and strengthen the root system.

Potting mixes and other manufactured soil blends don’t contain mycorrhizae, but you can add them before or during planting. Once you introduce the fungi, the colonization will happen quickly.

There are several ways to do this:

  • Mix them into the soil
  • Add them while transplanting from a pot
  • Use them while watering seeds or seedlings
  • Apply them as a coating on the root ball
  • Add them to transplant and backfill soil

Spore-Based Mycorrhizae vs Propagules

Even though most mycorrhizal products on the market are propagule-based, this does not mean they are the best form of mycorrhizae.

Propagules consist almost exclusively of fragile and fast-declining hyphal structures that cannot effectively colonize the roots. Scientific studies confirm these propagule components begin to die off only a few days after manufacturing, losing their viability and effectiveness, leaving only negligible amounts of active propagule structures. It is estimated that more than half of the propagules listed on a label will be dead and inactive 3 months from the date it was packaged. Rarely can a consumer hope to even purchase the product within this window.

Spores, on the other hand, are reproducing survival structures produced by mycorrhizal fungi. Because spores are more resilient to temperature fluctuations, they are able to remain viable even if manufacturing, storage, and transport conditions are not ideal. Spore-based mycorrhizae have a minimum shelf life of 2 years, often remaining viable up to 5. A single spore, when activated, will produce (on average) 50x more mycorrhizal mass than a single viable propagule.

Mycorrhizae Spores vs Propagules
IMAGE SOURCE: Mycorrhizal Applications

We chose the endomycorrhizal strain used in Trifecta Myco Supreme, Rhizophagus Irregularis, specifically for a few important reasons:

  • R. Irregularis is the most widely studied strain of mycorrhizae to date
  • R. Irregularis is known for being compatible with the widest range of plant species
  • R. Irregularis has been scientifically proven to be the most symbiotic strain for growing cannabis

Endomycorrhizae vs. Ectomycorrhizae: What is the Difference?

Two types of fungus colonize plants: endomycorrhiza or ectomycorrhiza.

Endomycorrhiza form relationships with 90% of all plant species. Endomycorrhizal fungus is also known as vesicular-arbuscular or VA mycorrhizae. It’s called vesicular-arbuscular mycorrhizae because it forms small storage sacs known as vesicles. Delicate structures known as arbuscules enter the living cells to help with the exchange of nutrients. These eventually lead to the development of hyphae, which extend outside of the root.

Endomycorrhizal fungi form mostly with fruiting and green, leafy plants. Most vegetables, fruit trees, flowers, grasses, ornamentals, and shrubs benefit from endomycorrhizal fungi. Most plant species form relationships with endomycorrhizal fungi.

Endomycorrhizae vs Ectomycorrhizae

Ectomycorrhizal fungi colonize from outside of the root cells, extracellularly. Ectomycorrhizal fungi form relationships mostly with woody plants/trees in forests and are found on most Conifer and Hardwood species. Ectomycorrhiza form relationships with approximately 10% of all plant species.

There are many different strains of mycorrhizae. Most of them, whether ecto or endo, only form relationships with a very limited number of plant species. A very few plant species, such as those in the family Brassicaceae, do not form any mycorrhizal relationships at all. There are others, such as the families Ericaceae and Orchidaceae, that require very rare, individualistic species of mycorrhizae. Rhizophagus Irregularis is unique in that it is the endomycorrhizae strain that is found colonizing the broadest range of plants, creating benefits for millions of different plant species globally every day.

How Long Does it Take for Mycorrhizae to Work?

Although the fungi go to work at once, it takes about a month for the colony to get fully established. Typically, you will have a significant, visible, measurable colony after the first month, but results can vary.

What is the Best Mycorrhizae Strain for Growing Cannabis?

Best Mycorrhizae for Cannabis
This is a user submitted photo of 2 cannabis plants, both treated with mycorrhizae. The plant on the left was treated using Trifecta Myco Supreme. The plant on the right was treated with a competitor product. It’s clear to see which brand is the best mycorrhizae for cannabis!

Many mycorrhizae strains will work on cannabis plants, but promising results have been seen in the use of rhizophagus irregularis. This strain is not specific to cannabis, but is the most beneficial mycorrhizae for cannabis and hemp plants.

A 2021 study of rhizophagus irregularis on cannabis tested the effects of this strain by applying three treatments to a group of cannabis seedlings. The researchers added 40, 80 or 120 fungal spores per liter of nutrient solution to each plant. They compared these test subjects with untreated plants.

The results were dramatic. They found that cannabis plants treated with the highest levels of fungi had an increase in root length of more than 30%. These plants also showed a higher dry weight of more than 20%. These plants also had significantly higher survival rates than plants treated without mycorrhizae.

Which Plants Don’t Form a Relationship with Endomycorrhizae?

Almost all plants benefit from mycorrhizae colonies. There are a few, however, that do not. They include azaleas, beets, blueberries, broccoli, Brussels sprouts, cabbage, kale, carnations, cauliflowers, collard greens, cranberries, heath grasses, huckleberries, mustard plants, protea plants, rhododendrons, sedges, and spinach.

How to Apply Mycorrhizae

Mycorrhizae products come in different types for different application methodologies.

  • Granular mycorrhizae products are applied as a powder and are typically not water soluble. Most mycorrhizae products available on the market are considered granular.
  • Soluble mycorrhizae products can be powders that are soluble in water or come in liquid form.
  • Trifecta’s Myco Supreme Premium Mycorrhizae can be used either as a granular or it can be mixed with water to apply as a liquid.

Below are instructions on how to apply each.

Granular Mycorrhizae Application Instructions

You can buy mycorrhizal granules in a powdered form that you apply directly to the soil. Here’s how to apply these granules to every stage of your gardening plan.

Seeds: Apply mycorrhiza granules directly into the planting hole, furrow, or seed pot before you plant the seeds. You can also add the granules directly to the seed packet and shake it. Follow the directions on the seed packet to get the right soil depth and watering schedule.

New plantings: New plants can also benefit from mycorrhiza granules. Add the granules directly to the root ball before you place the plant in the soil. You can also sprinkle it directly into the soil.

Potting soil: Use mycorrhizae in your potting mix to improve it. Many commercial potting soil mixes lack these beneficial fungi, and others rely on chemical fertilizers to promote plant growth. By adding these granules, you’re adding microorganisms that create healthy plants and high yields. If you’re using your own garden dirt as potting soil, adding these granules ensures healthy mycorrhizae colonies giving your plants the best chance of success.

Transplants: Like new plantings, transplants benefit from mycorrhizae to lessen transplant shock and make a successful transition to their new location. Add the granules to the root ball or soil before transplanting.

Established plants: Don’t just sprinkle the mycorrhizae on top of the soil. Sunlight inhibits the growth of fungi. It is important for the mycorrhizae to make direct contact with the plants roots in order to trigger colonization. One of the easiest ways to ensure this is to use a tool to poke multiple extrusions in the soil that reach to the roots. A long funnel into the extrusions can help deliver the material directly to the roots. Add small amounts into the funnel and tap to get the granules delivered to the roots.

Hydroponic plants: Mycorrhizae granules can be added to your growing medium during transplanting in hydroponic systems. If using rockwool the best practice is to apply mycorrhizae granules when transplanting from 1” cubes to 8” cubes by adding a good dusting of granules to the hole in the 8” cube prior to inserting the rooted cutting. It can also be beneficial to poke some extrusions into the 8” cube and shake the granules down into the rockwool.

How often should you apply mycorrhizae granules?

In most cases, a single application is enough to get your plants off to a good start. After that, regular applications every two to three weeks will keep your fungi healthy and growing. For transplants and seedlings, apply more mycorrhizae every 10 days throughout the transplantation process.

Soluble Mycorrhizae Application Instructions

Soluble mycorrhizae products can come in a powder or liquid form. Typically, you create the solution by mixing the product with water. For best results, use non-chlorinated water and follow the manufacturer’s instructions. Here’s how to use it at every stage of the plant’s life.

Seeds: Before planting your seeds, soak them in the solution for 8 to 12 hours.

New plantings: Apply the solution directly to the root ball. Be sure to thoroughly drench it. You can also add it to the hole before you insert the plant.

Potting soil: Drench the soil with soluble mycorrhizae when watering your plants. It will work equally well for potted plants and in-ground plants.

Transplants: Use the solution to soak the root ball before you transfer your plant to a new location. Start before you dig up the plant. Continue adding the solution every 10 days up to the final day of the transplantation process.

Potted plants: A soil drench works extremely well on potted plants. Use the solution to soak your plants.

Injection: If the ground is too hard to dig into easily, use the soil injection method. One of the easiest ways to ensure this is to use a tool to poke multiple extrusions in the soil that reach to the roots. Pouring the solution into the holes allows better direct root contact.

Hydroponic plants: A mycorrhizae solution can be added to your growing medium in hydroponic systems. As always full contact with the roots is the only way for the mycorrhizae to become viable.

Trifecta Myco Supreme Application Instructions

Add Myco Supreme directly to the growing medium so that the mycorrhizal spores make good contact with the plant’s roots. Set the plant and backfill. Be sure to water plants well after transplanting.

If transplanting into rockwool, poke several small holes in the bottom of the transplant hole in the cube and add Myco Supreme into the hole, shaking material down into the extrusions.

Potted Plants and Hydro Systems

  • Up to 1 Gallon Containers and Rockwool cubes up to 8”: 1 Teaspoon
  • Up to 3 Gallon Containers: 1 Tablespoon
  • 5 Gallon Containers and up: 2 Tablespoons

Raised Beds

Simply add 1 Teaspoon directly to the roots of your plant or in each plant hole prior to transplanting so the roots are in contact with the product. Be sure to water plants after transplanting.

Outdoor Transplants Directly into the Ground

2 Tablespoons or more as needed, such that a fine dusting of Myco Supreme covers the bottom of the hole where the plant’s roots will make contact.

Soil Drench Applications

Calculate the normal amount of water and Myco Supreme for an individual plant based on the container size or other characteristics described in the directions above. Slowly add Myco Supreme into the water with continual mixing until it dissolves and pour content around the roots. It is recommended to treat each plant individually to guarantee even and appropriate dosing.

The Perfect Partner Product for Pest Free Plants

If you’re in need of a natural solution to the problems of pests, mold, and mildew, turn to Trifecta Crop Control. Our all-natural pesticide will help you eliminate the most damaging garden pests while allowing your vegetables, flowers, and cannabis plants to flourish. It’s the most potent natural pesticide available. To learn what makes it a truly unique product, click here. The combination of Myco Supreme Mycorrhizal Root Inoculant and Crop Control means you’ll have happy healthy plants all season long!

References

Ecology of Plant-Microbial Mutualisms
The Ecology of Plant–Microbial Mutualism

Effect of Rhizophagus irregularis on Growth and Quality of Cannabis Sativa Seedlings
https://www.mdpi.com/2223-7747/10/7/1333

Frequently Asked Questions

How do you inoculate soil with mycorrhizae?

Granular mycorrhizae: These are granules or powders that you apply directly to the soil or the plant’s root system. They can also be mixed with seeds by placing them inside a seed packet.

Soluble mycorrhizae: This is a premixed liquid that you apply to root balls or the soil. Use this to drench the soil or to water established plants. Always be sure you reach deep into the plant’s root system when applying these fungi. They should be applied to damp soil covered with mulch. Sunlight prevents the growth of mycorrhizae.

No, you can’t use too many mycorrhizae. Unlike some fertilizers or soil additives, it does not damage your plants if you accidentally add too much. These fungi are beneficial, and even adding copious quantities won’t hurt your plants. For best results, follow the manufacturer’s instructions.

Mycorrhizae enhance plant nutrition by making the plant roots longer, stronger and more efficient. They create a second root system for the plant, and this root system penetrates deeply to pull water and nutrients from the soil. Strong plant roots grow healthy plants that can tolerate stress and less than optimal conditions including drought, pests, mold/mildew, and diseases.

Mycorrhizae help your plant absorb nitrogen and other nutrients. It’s important to note that adding chemical fertilizers containing high levels of nitrogen salts can have the opposite effect, however. These high chemical doses will reduce the activity of the mycorrhizae and can lead to a nutrient imbalance. To prevent this, avoid using synthetic fertilizers and stick with organic options that can reside in the soil and be used as needed by the plant and the mycorrhizae.

The fungi begin colonizing at once, but it takes about a month for the colony to become established. You will begin to see a noticeable difference in your plants after about the first month.

Yes, chlorine will kill mycorrhizae. Use non-chlorinated water for the best results.

Once they are in the soil, they will stay there unless they’re destroyed by chlorine, sunlight or other factors. To keep them strong and healthy, apply more mycorrhizal every two to three weeks.

Ectomycorrhizae are fungi that live on the surface of the plant’s roots. They exist on about 10% of all plants and are specifically found forming colonies in the roots of trees.

Endomycorrhiza are fungi that grow inside the plant’s roots. They extend the root system and make it more efficient. They are found on 80-90% of all plant species but rarely do these mycorrhizae colonize trees.

High pH levels in soils can slow the growth of mycorrhizae colonies. Most mycorrhizae prefer soils with low pH levels. However, studies have found that plants and fungi can change the pH levels in the soil when they work together.

When planting trees, flowers or shrubs that prefer acid soils, it is often a good idea to add sulfur or another acidifying compound to the soil. This temporarily lowers the pH level and allows the mycorrhizae to flourish. Once the fungi have set up their colonies inside the plant roots, they start improving the soil. Mycorrhizae help acidify the soil, which is beneficial for them and their host plants.