Potting soil with mycorrhizae

Creating Your Own Mycorrhiza

The roots of plants can only take in nutrients within its rhizosphere, or the area surrounding its roots. This area encompasses about 1/10 of an inch around the roots. Think about it. All that fertilizer, compost, water and whatever else you dump in the soil is only getting to the plant if it is 1/10 of an inch away from the roots. The rest is wasted. To better survive, the plants root system secretes out certain exudates (organic acids and sugars) to attract particular organisms (fungi and bacteria) for whatever micro-nutrient the plant is lacking. Fungi spread out in root-like stringy webs called hypha and bring the nutrients to the rhizosphere to trade them for the exudates. This basically increases the area of the plants rhizosphere and thus more access to nutrients for the plant.

This alone makes me want to use these little organisms in my garden, but a strong colony of beneficial fungi and bacteria crowd out the harmful ones leaving the plant in better condition. It helps the plant resist pests and diseases, helps the plants from overstressing, and can also increase drought tolerance. Many studies from around the world have shown the benefits of encouraging this symbiotic relationship. So while you can go buy specific species of fungi to add to your garden and fields’, making them on your own is as easy as creating an environment for what is already in the soil to thrive.

Creating Soil Helpers: They Work Hard So You Don’t Have To

Fungi and Bacteria are classified as decomposers. If they weren’t around we would quickly be swimming in un-decomposed organic matter. Though paradoxically, without them we would not have that organic matter in the first place. Bacteria are nitrogen loving and capable of ingesting only the simplest of micro-nutrients and sugars. Woody carbon-filled matter is what fungi are good at breaking down with the enzymes it creates. Knowing this I set out to establish different environments for both organisms to grow.

For the bacteria I made sure to have lots of small organic materials for them to munch on. Layering my compost pile with a good ratio of carbon to nitrogen ensures that the organic matter breaks down enough for the bacteria. Air and water are needed for this as well so a moist and aerated compost pile with plenty of brown and green material is a perfect breeding ground for beneficial bacteria. Lots of worms showing up in your compost pile are a sign of many decomposers present since this is the worm’s main diet. The excreted material leftover by the worms is also a great addition for soil fertility. I cover my compost pile with straw or leaves since UV light can kill the bacterial colonies you are encouraging to grow.


For the fungi I covered my low hoop tunnel bed last fall with straw while my remaining summer crops were wrapping up for the year. Before winter came I added a good amount of leaves I collected in the Compost Bandit over the top of the straw. This mulch covered the fungi within the soil and enabled them to grow around the straw. This method is easier than composting because it requires you to do the opposite; you don’t turn it. As mentioned earlier, fungi spread out with thin stringy webs called hypha. Turning and mixing the soil would destroy that hypha killing the network the fungi had created. This is why no-till or low-till is more beneficial in the long run than tilling the ground up every year. You are making it harder for the beneficial fungi to grow which limits their presence for the plants come spring time.

Before spring came this year, I carefully removed all the leaves from my garden bed exposing all the fungi that had been growing there. The next step was to add the bacteria filled compost directly on top. This gives me fungi, bacteria, and good compost to make my garden bed a fertile one for this year’s crops. When pulling out the few weeds that had managed to grow under the leaves, I saw the fungi all wrapped up in the roots. This was a good sign of things to come for the plants I wanted to grow there this year.

In a world where we are too impatient for things to come, it makes sense to find simple ways of doing things so we can more easily make the transition from short term thinking to long term. Growing beneficial fungi doesn’t take any work from you other than setting up an area that encourages growth. There is no tossing and mixing. There is no checking on it daily. It should be added to your end of the year garden preparation for winter. This will not only enable you to use less fertilizers and pesticides but will also make your plants all the more happier and healthier, passing those benefits on to you.

Sources: “Teaming with Microbes” by Jeff Lowenfels, Wayne Lewis

“Introduction to Micorrhizas,” Mycorrhizas.info


“Micorrhizal Effects on Host Plant Physiology,” Fred T. Davies Texas A&M University

“The Microbial World: Micorrhizas,” Jim Deacon, Institute of Cell and Molecular Biology, University of Edinburgh

Ylad Living Soils

These processes results in greatly improved chances for survival compared to non-mycorrhizal plants. Almost immediately, the colonised sprout develops special “tools” to secure adequate moisture, nutrients and defense against fungal root diseases. The hyphae quickly grow and spread through-out the surrounding soil, penetrating the tiny spaces between soil particles. As they encounter more roots, these also become colonised. Then, each of these roots produce more hyphae which, in turn colonise even more roots until a massive hyphal network has pervaded the expanded rhizosphere.

Clearly, inoculating seeds with Mycorrhizae is an effective way to go. The benefits are the greatest and the cost is minimal, since treating a seed usually takes less inoculums than is required to colonise the larger root system or a more developed plant.

Seed treatment is best accomplished using either powdered or liquid mycorrhizal inoculants applied so that the inoculums adhere directly to the surface of the seed. Powdered inoculants work well with hairy-textured seeds such as wheat, barley, oats, or many grass seeds. Seed adhesion is important not only to insure inoculums proximity to the germinating seed, but because excess powder falling off the seeds can accumulate in the seed box, possibly leading to mechanical problems with the auger and drill operation of the planting equipment.

Liquid inoculums are often preferred for corn, beans, Lucerne and similar smooth-surfaced seeds because it will adhere well.

Application to the seed can be achieved by lightly spraying liquid inoculums on the seed as it passes on the conveyor to the seed box on the planter.

Often liquid inoculums can be applied to seed by mixing it with other seed treatments such as legume inoculants on beams, alfalfa and vetch –

YLAD Living Soils mix their proven seed treatment Seed Start with the Platform to create a complete seed dressing.


Liquid mycorrhizal inoculums can be sprayed in-furrow along or with other liquids. While this later technique does not inoculate the seed immediately upon germination, the young plants become colonised as their roots enter the treated bands. This latter method often dovetails will with fertiliser or other planting applications.


Plants may also be treated after planting, including established crops and pastures. This method of inoculating is quite common with vegetables.

Treating established crops is particularly worthwhile with perennial crops such as Lucerne in which a one-time inoculation will continue to deliver benefits over several years. The amount of inoculant used to treat such a crop is greater (and therefore also the cost) but the advantages apply to multiple harvests.

Forage pastures are another excellent example whereby either a one-time or a few incremental applications can afford very long term benefits.


When applying a mycorrhizal inoculant at planting, it is important to avoid high levels of available phosphorus in the soil proximate to the target seed or roots. Readily available soil phosphorus in excess of approximately 70 ppm can prevent the mycorrhizal spores in an inoculant from breaking dormancy when in near contact with a live root. Since one of the primary natural functions of the mycorrhizal relationship is to access and mobilize phosphorus, the spores have been ‘programmed’ to delay activation in an abundant phosphorus environment. The propagules are not harmed and do not expire under such circumstances, however they remain dormant and colonization does not commence until the ambient phosphorus levels diminish. Insoluble forms of phosphorus that naturally occur in the soil do not contribute to this phenomenon. Likewise phosphorus from organic or natural fertilisers such as soft rock phosphate, humates, fish fertilisers or kelp is not problematic. It is the realty available phosphorus, derived primarily from soluble (liquid) or fast-release fertilisers that contribute to this situation. The solution is to avoid high rates of P starter fertilisers. Remember that one of the primary reasons for high P in starter fertilisers is to overcompensate for the inefficiency of non-mycorrhizal roots. Once crop plants become colonised with mycorrhizal fungi, these high P levels are no longer required. Phosphorus fertillisers applied anytime 10 – 20 days after inoculation and colonization has occurred need not be restricted.

NOTE: however, due to the greatly improved phosphorus uptake efficiency imparted by the mycorrhizal association, amounts of P fertilisers needs for good crop performance may be noticeably reduced.

Trials in Eyre Peninsula soils have shown that wheat inoculated with AM fungi was highly colonised and that the fungi delivered up to 80% of the plant phosphorus.


How do you tell if an application of mycorrhizal inoculant is working?

  1. When trialing any change in program, be sure to leave a part of your crop untreated as a control.
  2. Often the effects of mycorrhizal colonization will be obvious in early growth. The plants may be taller, have more foliage and larger root systems. If water is scarce, you may note less moisture stress compared to controls.
  3. Sometimes the visual difference between the treated and control crop is less obvious but the yields are significantly better in the treated crops.. And occasionally, there will be no discernable difference at all.
  4. In this last circumstance, it may be that the benefits lie entirely in savings via reduced inputs to get the same yields as without treatment. Capitalising on this may take some experimenting over several seasons.


Once you have re-established Mycorrhizae on your crops, there’s not much that will remove them from the living roots, but there are a lot of things that will help them colonise quicker, more thoroughly and increase the density of the hyphal network. What do compost, compost teas, no-till methods (with reduced chemical usage), humates, seaweed extracts and fish fertilisers have in common? All of them, in diverse and various ways, increase the microbial activity in the soils, including the mycorrhizal fungi which then spread from root to root faster and further enhance the nutrient uptake efficiency of the colonised plants.’

Scientific research confirms that fallow, frequent tilling, erosion, compaction and high levels of soil phosphorus availability delay, reduce or eliminate the soils AM populations.

Advancement in our understanding of mycorrhizal fungi and their requirements has led to the production of concentrated, high quality mycorrhizal inoculants such as Platform™.

The most important factor for re-integrating Mycorrhizae into the cropland environment is to place mycorrhizal propagules near seed or near the root systems of the target plants.

Ref: Dr Mike Amaranthus

Whatever course you decide upon,

There is always someone to tell you

that you are wrong

There are always difficulties arising

which tempt you to believe

that your critics are right.

To map a course of action and follow it

to an end requires courage.

Ralph Waldo Emerson (1803 – 1882)

DIY way to make mycorrhizal fungi

This is a cool technique that I read about on Rodale’s website, I’ve been wanting to try it for years.
Another technique that I do use, but I don’t know that it actually spreads mycorhizae, is coloquially called ‘fungal flats’. I have been told that it actually cultures actinomycetes, but in any case it seems to make plants happy. The recipe is as follolws:
2 parts high quality compost
1 part high humate soils (alaska humisoil is a nationally available brand)
1 part worm castings
1/8 part humic acid
1/8 part oceanic hydrolysate
you mix the ingredients all together and then cover in a high humidity situation for 3-7 days. the medium will become covered with white fuzz and can be used to innoculate transplant holes, add to compost teas, or spread under mulch as a top dress.
I typically use 2 cups as a ‘part’ in the above recipe and put the resulting ~8 cup mixture into a planting tray with a humidity dome on it with any vents just cracked. Once the surface is fully white and fuzzy I either use little chunks as innoculant under transplants or use about 1/3 of a tray in a 50 gallon batch of tea.
Total cost per tray has to run under 5$, might be much less

Here’s how to grow more mycorrhizal fungi

Advice about boosting the health of arbuscular mycorrhizal fungi is probably best started with the list of three “do-not” commandments.

1. Do not till. Tillage breaks up the myriad of hyphae/mycellium, most of which can never reconnect. Once broken, they must start all over, says Wendy Taheri, an expert on arbuscular mycorrhizal fungi. Dramatically shorter mycellium equals dramatically reduced plant food for your crops or forages. One source says it is not uncommon to have 20 meters of fungal root in one cubic centimeter of soil. Calculate that out to just the top inch of soil in an acre and you get a length that would stretch about 80% of the way to the moon; roughly 195,000 miles of food collectors per acre, all interconnected, all sharing stuff.

2. Do not provide much phosphorus. Taheri says too much phosphorus fertility in the soil, especially with crops and farm ground, can be almost as damaging as tillage. The plants latch onto the inorganic phosphorus source when young and never develop much of a trading relationship with the AMF. Remember that phosphorus is so necessary to plant life and so generally unavailable in a natural setting, that plants are programmed to make most of the trade deals with AMF based first on the need for phosphorus. You want the plants to be a bit hungry for phosphorus, Taheri says. For example, 200 ppm of phosphorus in a soil test is usually considered adequate for crop growth. If you want AMF to successfully colonize and trade with your plants, 50-100 ppm is a more AMF-encouraging range for phosphorus fertility.

3. Avoid pesticides as much as possible. Although AMF have a lot of resistance to even such compounds as fungicides, Taheri says most pesticides can be hard on AMF. The more you put on and the more frequently and the more you rotate pesticides, the more you will damage your AMF.

4 good things to do

1. Diversity is key. Manage for diversity above ground to build mycorrhizal and microbial diversity below ground. Although varied species of AMF tend to favor certain species or types of plants, their interactions directly and/or through microbial relationships, will add benefits at a compounding rate.

Plant roots become colonized by many species of AMF. Some are better at taking up water, others may be good defenders against certain pathogens, some relieve other environmental stresses such as soil compaction or excessive salinity. More is better.

Virtually every other trace mineral plants need for good health is provided by AMF, and those nutrients pass up through the food chain. Research has shown that plants associating with AMF have a higher nutrient density than the same plants without AMF.

2. Graze right. Use multi-paddock, adaptive grazing to alternate the natural pulse of grazing and defoliation with fairly lengthy recovery periods. This was a common behavior in the drier environments where large herds of ruminants grazed for hundreds of thousands of years. If done well, such forages can develop deeper, more highly functioning root systems. Also remember that cattle speed up the nutrient cycling by turning forage into urine and manure, which are more available forms of nutrients. Early scientific examination of these practices suggests this kind of controlled grazing will build soil fungal populations and overall productivity. Further, a study in North Dakota showed recovery time between grazing periods increased AMF.

Texas Agri-Life Extension

A study of three ranches with similar habitat and soils, but different management, showed that multi-paddock adaptive grazing produced the most soil life, and especially the highest fungal-to-microbial ratio.

3. Keep the soil covered. Leaving ample plant material on the soil surface at all times keeps it cooler and captures more rainfall. This is good for all soil life, which needs moderate temperature and moisture to function.

4. Develop a long growing season. The longer you can keep things growing in the soil, the more opportunity to feed the microorganisms. Diversity helps a lot in pastureland, and multi-species cover crops do that in crop ground.

Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Client’s Request: I went on Tuesday evening to a very good presentation at the Lafayette Library by Master Gardeners. I had a question that the presenters could not answer and their advice was to ask it directly to the Help Desk — so, here it is….
I have planted a new garden with native plants and have not added any amendment to support the plants’ growth. I read online that mycorrhizal fungi can be added after the plant has been set in the ground and it will enable healthier root and plan growth. Is that correct?
Help Desk Response: Thank you for contacting the UC Master Gardener program regarding mycorrhizal fungi and your native garden. We know that plants and mycorrhizal fungi live in a symbiotic relationship, very beneficial to both species. The fungi colonize the plant roots, helping with uptake of water and minerals. It is well known that plants in healthy soils with good mycorrhizal colonization are much healthier. You can promote this by appropriate irrigation, minimizing soil disturbance by not tilling, and limiting fertilizer, especially phosphorus. Also, using a surface mulch will help.
There have been many studies on the effects of mycorrhizae on growing plants, which show definite benefits, but it is not clear that adding them to an existing landscape is helpful. There are many different species of mycorrhizae, and it seems that they need to be adapted to the particular environment or plant species, and if you add ‘foreign’ ones, those native fungi already present may defend their territory and your garden will receive little or no benefit. Also, one study that I know of looked at viability of commercially available mycorrhizae inoculants and found that some did not have any live ones! That being said, if you still want to try this, a reputable and appropriate source should be used.
If your garden was prepared appropriately, and the plants are healthy and thriving, and you are using mulch, it should be fine without adding the mycorrhizae. In addition, I could not find any recommendation to add mycorrhizae for this situation on the California Native Plant Society website: http://www.cnps.org/cnps/grownative/getstarted/starting_a_garden.php
I hope this has been helpful and that your garden will thrive. If you have further questions, please feel free to contact us again.
Help Desk of the UC Master Gardener Program of Contra Costa County (SMW)


North Dakota State University

The word Mycorrhizae comes from the Greek words for fungus and root, meaning “fungus roots.” These fungus roots develop as a mutually beneficial relationship between plant roots and fungi that live in healthy soils. This relationship is found on about 90 percent of all land plants around the world, including most conservation and landscape trees in North Dakota. These fungi that attach themselves to plant roots and act as extensions of plant root systems are called Mycorrhizal fungi.

A single square inch of soil can have miles of these fungus root extensions, called mycelium. This dense web of threads can improve plant health in different ways. In exchange for what the fungi offer, plants feed them with sugars produced through photosynthesis.

Benefits of Mycorrhizal Fungi

Water and Nutrient Uptake

Roots with mycorrhizal fungi are able to use water and nutrients that “naked” roots cannot reach by themselves. The extremely small fungal threads are able to reach water trapped in small soil pores. This not only improves plant growth, but it also can increase the chance of survival during drought.

Likewise, the threads can access nutrients in mineral deposits, soil aggregates and organic matter with pores too small for roots to grow into. Many forms of mycorrhizal fungi also are able to produce chemicals that break down soil compounds into forms that are easier for trees to absorb and use.

Pest and Disease Resistance

By improving water and nutrient uptake, especially phosphorus, fungi can improve tree health and increase trees’ abilities to fight off pests and disease. Some fungi also protect trees from soil-borne disease and pests by producing antibiotic compounds, stimulating other beneficial microorganisms in the root zone, activating plant defense genes, out-competing harmful fungi and acting as armor around fragile roots.

Survival in Harsh Soils and Overall Soil Health

Some mycorrhizal fungi can help trees tolerate soils with high or low pH, high salt content, low fertility or heavy metals. The way these fungi help trees survive in such difficult sites is not completely understood. However, much of the benefit comes from trees’ increased ability to take up extra moisture and nutrients, and by locking away potentially harmful chemicals in plant or fungus tissue.

Mycorrhizal fungi not only can increase tree survival in difficult soils, they can improve soil through time. Fungal roots help chemically and physically break up compacted soils. These processes also can help improve soils structure by promoting soil aggregates. The improved soil structure can reduce erosion, increase water infiltration and promote the growth of other beneficial soil-dwelling life forms.

Food for Wildlife

Some forest fungi rely on animals to spread their spores. These fungi produce fruiting bodies, commonly called mushrooms or sporocarps, directly above or below the soil surface. These can be excellent sources of protein, carbohydrates, minerals and water for many kinds of wildlife.

The spores are spread as animals dig for the fruiting bodies or as they carry the spores on their bodies or in their stomachs. Some of the better known sporocarps, such as morels, can be eaten by humans and are very valuable.

Some well-known mycorrhizal fungi, such as these morels, are important for wildlife and can be collected to be eaten or sold. Never eat or handle a sporocarp (mushroom) that a knowledgeable person has not positively identified as nonpoisonous. (Photo courtesy of North Dakota Forest Service)

Encourage Beneficial Fungi

Maintain Native Fungus Populations

Beneficial fungi occur naturally in North Dakota. These fungi are adapted to the local soil, climate and plant species. However, activities such as tilling, leaving cultivated land fallow a long time, high fertilizer or pesticide applications, and the removal of plant litter or woody debris all can reduce fungal growth. If tree planting site preparation includes tilling or herbicide application, much of the beneficial native fungi likely have been destroyed, and adding a commercially available blend of beneficial fungi could improve overall tree health and survival rates.

Buy Inoculated Seedlings or Inoculate in the Field

Trees can be inoculated (infected) with beneficial fungi in the nursery, while being out-planted with granular or liquid products, or after planting using a root drench. Buying trees already colonized with fungi or applying fungi on seedling roots using an inoculant at planting time are the most effective ways to colonize tree roots with good fungi.

Limit Fertilizer and Fungicide Use

High soil fertility actually reduces the development of many mycorrhizal fungi. Large applications of fertilizer, especially ones high in soluble phosphorus and nitrogen, should be avoided. Most foliar fungicide sprays will not affect mycorrhizal growth. However, root drenches of systemic fungicide can kill good fungi along with harmful fungi. Carefully read product labels and follow label directions on any chemical being applied around trees and shrubs to reduce the chance of harming helpful fungi.

High-quality nursery stock often already is inoculated with a mix of beneficial fungi. These fungi may appear as a white fuzz on or around roots. This fuzz is not alarming as long as seedlings appear healthy. (Photo courtesy of Mycorrhizal Applications, Inc.)

January 2016

Natural Resources Conservation Service

Soil Fungi

By Elaine R. Ingham


Fungi are microscopic cells that usually grow as long threads or strands called hyphae, which push their way between soil particles, roots, and rocks. Hyphae are usually only several thousandths of an inch (a few micrometers) in diameter. A single hyphae can span in length from a few cells to many yards. A few fungi, such as yeast, are single cells.

Hyphae sometimes group into masses called mycelium or thick, cord-like “rhizomorphs” that look like roots. Fungal fruiting structures (mushrooms) are made of hyphal strands, spores, and some special structures like gills on which spores form. A single individual fungus can include many fruiting bodies scattered across an area as large as a baseball diamond.

Fungi perform important services related to water dynamics, nutrient cycling, and disease suppression. Along with bacteria, fungi are important as decomposers in the soil food web. They convert hard-to-digest organic material into forms that other organisms can use. Fungal hyphae physically bind soil particles together, creating stable aggregates that help increase water infiltration and soil water holding capacity.

Soil fungi can be grouped into three general functional groups based on how they get their energy.

  • Decomposers – saprophytic fungi – convert dead organic material into fungal biomass, carbon dioxide (CO2), and small molecules, such as organic acids. These fungi generally use complex substrates, such as the cellulose and lignin, in wood, and are essential in decomposing the carbon ring structures in some pollutants. A few fungi are called “sugar fungi” because they use the same simple substrates as do many bacteria. Like bacteria, fungi are important for immobilizing, or retaining, nutrients in the soil. In addition, many of the secondary metabolites of fungi are organic acids, so they help increase the accumulation of humic-acid rich organic matter that is resistant to degradation and may stay in the soil for hundreds of years.
  • Mutualists – the mycorrhizal fungi – colonize plant roots. In exchange for carbon from the plant, mycorrhizal fungi help solubolize phosphorus and bring soil nutrients (phosphorus, nitrogen, micronutrients, and perhaps water) to the plant. One major group of mycorrhizae, the ectomycorrhizae (see third photo below), grow on the surface layers of the roots and are commonly associated with trees. The second major group of mycorrhizae are the endomycorrhizae that grow within the root cells and are commonly associated with grasses, row crops, vegetables, and shrubs. Arbuscular mycorrhizal (AM) fungi are a type of endomycorrhizal fungi. Ericoid mycorrhizal fungi can by either ecto- or endomycorrhizal.
  • The third group of fungi, pathogens or parasites, cause reduced production or death when they colonize roots and other organisms. Root-pathogenic fungi, such as Verticillium, Pythium, and Rhizoctonia, cause major economic losses in agriculture each year. Many fungi help control diseases. For example, nematode-trapping fungi that parasitize disease-causing nematodes, and fungi that feed on insects may be useful as biocontrol agents.

Many plants depend on fungi to help extract nutrients from the soil. Tree roots (brown) are connected to the symbiotic mycorrhizal structure (bright white) and fungal hyphae (thin white strands) radiating into the soil.

Credit: Randy Molina, Oregon State University, Corvallis. Please contact the Soil and Water Conservation Society at [email protected] for assistance with copyrighted (credited) images.

Fungus beginning to decompose leaf veins in grass clippings.

Credit: No. 48 from Soil Microbiology and Biochemistry Slide Set. 1976. J.P. Martin, et al., eds. SSSA, Madison WI. Please contact the Soil and Water Conservation Society at [email protected] for assistance with copyrighted (credited) images.

Ectomycorrhizae are important for nutrient absorption by tree and grape roots. The fungus does not actually invade root cells but forms a sheath that penetrates between plant cells. The sheath in this photo is white, but they may be black, orange, pink, or yellow.

Credit: USDA, Forest Service, PNW Research Station, Corvallis, Oregon. Please contact the Soil and Water Conservation Society at [email protected] for assistance with copyrighted (credited) images.

The dark, round masses inside the cells of this clover root are vesicules for the arbuscular mycorrhizal fungus (AM).

Credit: Elaine R. Ingham. Please contact the Soil and Water Conservation Society at [email protected] for assistance with copyrighted (credited) images.

Where Are Fungi?

Saprophytic fungi are commonly active around woody plant residue. Fungal hyphae have advantages over bacteria in some soil environments. Under dry conditions, fungi can bridge gaps between pockets of moisture and continue to survive and grow, even when soil moisture is too low for most bacteria to be active. Fungi are able to use nitrogen up from the soil, allowing them to decompose surface residue which is often low in nitrogen.

Fungi are aerobic organisms. Soil which becomes anaerobic for significant periods generally loses its fungal component. Anaerobic conditions often occur in waterlogged soil and in compacted soils.

Fungi are especially extensive in forested lands. Forests have been observed to increase in productivity as fungal biomass increases.

In arid rangeland systems, such as southwestern deserts, fungi pipe scarce water and nutrients to plants.

Credit: Jerry Barrow, USDA-ARS Jornada Experimental Range, Las Cruces, NM. Please contact the Soil and Water Conservation Society at [email protected] for assistance with copyrighted (credited) images.

Mushrooms, common in forest systems, are the fruiting bodies made by a group of fungi called basidiomycetes. Mushrooms are “the tip of the iceberg” of an extensive network of underground hyphae.

Credit: Ann Lewandowski, NRCS Soil Quality Institute. Please contact the Soil and Water Conservation Society at [email protected] for assistance with copyrighted (credited) images.

Mycorrhizal Fungi in Agriculture

Mycorrhiza is a symbiotic association between fungi and plant roots and is unlike either fungi or roots alone. Most trees and agricultural crops depend on or benefit substantially from mycorrhizae. The exceptions are many members of the Cruciferae family (e.g., broccoli, mustard), and the Chenopodiaceae family (e.g. lambsquarters, spinach, beets), which do not form mycorrhizal associations. The level of dependency on mycorrhizae varies greatly among varieties of some crops, including wheat and corn.

Land management practices affect the formation of mycorrhizae. The number of mycorrhizal fungi in soil will decline in fallowed fields or in those planted to crops that do not form mycorrhizae. Frequent tillage may reduce mycorrhizal associations, and broad spectrum fungicides are toxic to mycorrhizal fungi. Very high levels of nitrogen or phosphorus fertilizer may reduce inoculation of roots. Some inoculums of mycorrhizal fungi are commercially available and can be added to the soil at planting time.

Mycorrhizal fungi link root cells to soil particles; sand grains are bound to a root by hyphae from endophytes (fungi similar to mycorrhizae), and by polysaccharides secreted by the plant and the fungi.

Credit: Jerry Barrow, USDA-ARS Jornada Experimental Range, Las Cruces, NM. Please contact the Soil and Water Conservation Society at [email protected] for assistance with copyrighted (credited) images.

  • Contains: Compost, Coco Fiber, Pecan Mulch, Perlite, Mushroom Compost, Molasses, Native Recycled Trees and Shrubs
  • Resists Clumping
  • Peat Moss Free
  • Contains Mycorrhizal Fungi
  • Holds Moisture
  • Kid and Pet Friendly

Nature’s Creation® Organic Potting Soil with Mycorrhizal Fungi readily absorbs water, no more having to stand there and water while most of it runs right through the pot. It holds moisture without becoming saturated. The soil dries evenly which all but eliminates fungus gnats and mold. Nature’s Creation® Organic Potting Soil with Mycorrhizal Fungi contains no peat moss.

Nature’s Creation® Organic Potting Soil with Mycorrhizal Fungi is a blend of weed-free and naturally sterilized Compost plus Coco Fiber which resists clumping and adds porosity. In addition, the blend includes Pecan Mulch, Perlite, Mushroom Compost, Molasses and Native Recycled Trees and Shrubs. Finally, a blend of the most effective Vascular Arbuscular Mycorrhizal Fungi is added to the mix.

Benefits of Mycorrhizal Fungi

Mycorrhizal Fungi exist in symbiotic relationship with plant roots. Mycorrhizal literally means fungus root. Nature’s Creation® Organic Potting Soil with Mycorrhizal Fungi contains 11 different strains of the genera Glomus, Rhizopogon, Pisolithus and Scleroderma. Mycorrhizae are divided into two basic classes, Endo and Ecto. The Endomycorrhizae actually penetrate roots to help capture nutrients and micronutrients from the soil. Ectomycorrhizae work mainly with woody plants forming what is commonly known as the Wood Wide Web. Both types benefit the host plants by increasing drought tolerance, water and nutrient uptake and disease resistance.



Select a pot with drain holes. If the pot does not have a hole, fill bottom 2 – 3 inches with small rocks and activated charcoal for drainage. Fill pot 1/3 with Nature’s Creation® Organic Potting Soil with Mycorrhizal Fungi. Place the plant in the center of the pot and fill to the top of the root ball and gently firm the soil. Water gently and allow to drain.


For repotting, lightly tap side of pot containing plant and remove gently. Loosen the root ball of the plant. Place plant in the center of the new pot and add enough soil to maintain the height of the ball. Fill the pot to within 1 inch of the top with Nature’s Creation® Organic Potting Soil with Mycorrhizal Fungi. Water slowly and allow to drain.

Seeds & Cuttings

Fill tray with Nature’s Creation® Organic Potting Soil with Mycorrhizal Fungi. Plant using seed packet directions. Cover seeds with 1/4 to 1/2 inch of soil. Water gently daily. Do not drench.

For cuttings, make a small hole in the soil. Place root stem in hole and cover with soil. Gently water daily


Mycorrhizal root tips (image by Thergathon)

Mycorrhizae (pronounced My-cor-rye-zay) are fungi that form mutually beneficial relationships with the roots of certain plants. These fungi have mycelium that either grow either inside of a plant’s roots (Endomycorrhizae) or attach to root surfaces (Ectomycorrhizae). Both the fungi and plants benefit. The fungi benefits from the plant’s food and nutrients, and the fungi send out their hyphae (like small roots) out into the surrounding soil to absorb additional nutrients and water, which benefits the plants.

So, mycorrhizae actually enhance a plant’s ability to take up nutrients and water. Because of this, research has shown that the presence of mycorrhizae helps plants better withstand drought and some diseases. Approximately 95% of the world’s plants have some form of mycorrhizal dependence. As far as growing is concerned, in many cases, increased root and top growth occurs when plants are treated with mycorrhizae. These benefits are not always evident, especially on short term crops, unless the crop is stressed or planted into a landscape where water and nutrients are less available.


There are two main types of mycorrhizae – Ectomycorrhizae and Endomycorrhizae. Both types develop certain plant-fungi associations. Ectomycorrhizae species form relationships with birch, oak, spruce, pine and fir trees but are not important to most greenhouse growers.

Endomycorrhizae, which are also known as vesicular-arbuscular mycorrhizae or VAM, are far more common and develop relationships with many economically important herbaceous plants. Around 80% of all the plants in the world form associations with different species of endomycorrhizae. This includes nearly every greenhouse plant. These are the mycorrhizae that are important to greenhouse growers.


It is not difficult to create a good environment for endomycorrhizal (VAM) colonies. Simply plant the right host plant with the right endomycorrhizae and you are set. The proprietary mix of endomycorrhizae selected for Sunshine Advanced mixes will colonize many species of greenhouse plants, so growers can be confident in choosing our myco-enhanced mixes! From there, several growing conditions need to be considered.

The primary environmental factor of concern is the amount of inorganic phosphorus in your growing system. The relationship between mycorrhizae and their host plants evolved to help the plants access low levels of available phosphorus in the soil, so mycorrhizae do not grow and colonize roots at high phosphorus levels. Phosphorus levels above 10 ppm in the soil solution will negatively impact the growth and establishment of mycorrhizae. High phosphorus levels do not kill the mycorrhizae but create an environment where they will not grow, and this renders them ineffective. As a grower, you should use low phosphorus feeds for the first 30 days to allow mycorrhizae to grow.

Chemical fungicides should be avoided, but if their are needed, wait to use them until enough time has elapsed to allow root colonization to occur. Four to six weeks should provide ample time.


The Sun Gro technical team has found excellent colonization results when mycorrhizae are added to Sunshine Advanced grow mixes. Organic fertilizers release their nutrients slowly over time, so the levels of phosphorus remain within a tolerable range for good mycorrhizal growth and colonization. Since we wish to supply our customers with the best performance, we offer two top-quality grow mixes with mycorrhizae, Sunshine® Advanced Mix #4 Growing Mix, Sunshine® Mix #4 Aggregate Plus with Mycorrhizae, Sunshine Advanced Rain Forest Blend, and Sunshine Advanced Ultra Coir.


Other media products in the market offer single species of endomycorrhizae or a blend of endo and ecto mycorrhizae. Sunshine Advanced mixes with mycorrhizae use a blend of endo species designed to enhance colonization under a wide range of growing conditions. We do not add ectomycorrhizae since they provide no benefit to most greenhouse crops.

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