FungiSoil BiologySoil RehabilitationStructure

Fungal Soil: What Is It and Why Do We Want It?

Look at all those Fun Guys! Do not eat! Little brown mushrooms can be poisonous…
and extremely whimsical.

Wood chips make a good mulch for woody plants. To go a step further, you want to use ramial wood chips, which are wood chips made from the outer reaches of a deciduous tree. That means the smaller branches, including the leaves if possible, and not so much the trunk and thicker branches (the rule of thumb is nothing more than 2.5 inches thick).

Why do we want ramial wood chips?

It’s because we want a fungal dominant soil. We want a soil that’s full of the beneficial fungi that help woody plants grow vibrantly and resiliently.

The term ramial is based on a french word, rameal, which means ‘related to the small branch’. It was coined by the French Canadian, Prof. Gilles Lemieux, who pioneered the research.

The ideal soil for woody plants contains beneficial fungi and these ‘fun guys’ thrive with the addition of ramial wood chip mulches. This type of mulch has the optimum balance of carbon to nitrogen and higher nutrient content than other wood chips. This optimum balance is due in large part to the greater ratio of cambium and recently living cells vs. old dead wood cells. It makes sense that using wood chips made with more live tissue or recently-living tissue will have more nutrient value than chips made from older wood, which is mostly carbon.

It’s like if we were to eat an animal, we’d want to eat the meaty areas and organs for the nutrients. We don’t want to eat hair, bones, and cartilage.

So for feeding fungi, the ideal wood chips should be obtained from freshly cut smaller branches with the leaves still on them. That’s where the most nutrients reside and the good fungi love that.

What do the Fungi do?

Beneficial fungi are certain species of fungi that protect our plants from disease by:

  • Out-competing disease organisms
  • Creating a healthy soil biology
  • Offering direct protection to our plants by producing anti-pathogens
  • Providing nutrients and water directly to the plants for better plant health

Quick quiz: Does anyone remember where the antibiotic ‘Penicillin’ came from?

Answer: It’s a compound originally produced by certain Fun Guys to ward off the Bad Guys!

What we call mushrooms are the fruiting or reproductive spore-producing structures of
the fungi. The actual ‘body’ of the fungi live within the soil and consist of string-like hyphae
that form interwoven string networks. These networks have a massive surface area and
are very effective at extracting nutrients and water from the soil and mulch.

One type of fungi, called mycorrhizal fungi, physically attaches to the roots of woody plants and extend the ‘reach’ of the plant’s roots, mining for water and nutrients in the soil that plants have a hard time accessing with their own roots alone.

The body of fungi, called mycelium, consists of strands that form massive ‘string networks’ within the soil and have tremendous surface area contact with the soil. This fungi network is more efficient at gathering water and nutrients than a plant’s roots are.

The fungi feed the woody plants with the nutrients and water that it has extracted from the soil, and the woody plants feed the fungi food sugars it has produced via photosynthesis, which the fungi cannot produce itself. Fungi do not photosynthesize, this is one of the major characteristics that distinguish fungi from plants.

The connection between the fungi and the plant’s roots is intracellular. There is chemical communication going on along with the nutrient exchange. The relationship is symbiotic and has evolved over thousands of years. It has been shown that it goes further than one fungus and one plant; that the fungi connect nearby plants to each other as well. The chemical communication goes on between multiple plants via the fungi.

The forest is one

In forests, it has also been shown that when trees die, they channel their remaining nutrients out into the fungi web to feed other trees. Or a sick tree may receive nutrients from healthier trees. The term ‘mother tree’ has been applied to the largest trees in a forest as these matriarchs actually preside over the health and well being of all the surrounding trees.

The forest is one.

Okay, that might be an exaggeration, perpetrated for dramatic reasons, but many trees are connected together and it’s hard to tell how far it extends. So, in an old growth forest, perhaps it is possible. The point is that, at the very least, it is a network. Who knew the very first Internet was invented by fungi.

It’s interesting that we did not discover this fact until very recently. We divided the plants into the plant kingdom and the fungi into the fungal kingdom and assumed these two abided by our abstract separation; rival factions following the ‘laws of the jungle’, doomed to compete for the same resources ’til the end of time, an adversarial relationship.

We were wrong.

You could say we couldn’t see the forest for the trees. We were reductionist instead of holistic. It seems to be a common human flaw.

Luckily, we know better now. Now it is our duty to restore and encourage these systems, for greater ecosystem health and benefit. That includes us.

An interesting parallel in human health

We are now discovering that our own health depends on the health of the microbes in our gut. Just like mycorrhizal fungi have a symbiotic relationship with plants — helping the plants by increasing nutrient uptake and offering disease protection in exchange for food — the bacteria in our gut, in a similar role, offer our bodies nutrients and protection in exchange for comfortable living quarters within us (all the meals you can eat and a cozy 37°C all the time!)

By conservative estimate, in a healthy human, there are more beneficial bacterial cells in our body than there are human cells in our body. It is also evidenced that if we lose or kill off these beneficial organisms in our gut, we can become sick very quickly, even exposing us to the possibility of death.

This reframes everything. A classic paradigm shift. We can now think outside the box that we made for ourselves.

We as individual humans are not an organism. We are ‘we’. We are a super-organism.

Who are we really! More ‘germ’ than human?

Fungi comes in fun colors and shapes! Wait, is that poisonous?

Back to the wood chips….

What about coniferous wood chips?

When sourcing wood chips, not only is ramial chips what you’re looking for but it’s also preferable to avoid coniferous wood chips as they tend to have naturally produced compounds that inhibit beneficial fungal growth. Coniferous wood chips actually feed a different sort of fungi that produces allelopathic compounds that inhibit beneficial fungi and decay.

However, coniferous wood chips are still better than bare soil. Keep that in mind if that’s all you have available. In that case, if you think your plants are being stunted by the coniferous wood chips, you could consider top-dressing the wood chips with compost or manure to help overcome the anti-good-fungus properties of conifer wood chips. Both compost and manure bring a litany of microbial ‘helpers’ to assist with the breakdown of the unwanted compounds as well as providing nutrients directly to plants.

These ‘Ink Cap’ mushrooms metamorphose from soft fuzzy domed caps, opening delicate
translucent parasols, and finally melting into a inky black globs like something out of
a horror movie.

So, how can you tell you have a fungal soil?

One way, the crude method, is to dig into your mulch/soil interface and see if it’s populated by white strands. These are the hyphae strands, the mycelium, or ‘body’ of the fungi. Although, I wouldn’t recommend digging stuff up if you don’t have to. It disturbs and kills the fungi to expose it and breaks its hyphae connections. Don’t worry though, if the conditions are right and the soil is well populated, it will undoubtedly recover.

Do you see the mycelium in this recently overturned wood chip mulch? The white patches
and strands are the body of the fungus. Notice how it is in close contact with the chips
and how it binds loose chips together in clumps.

A less intrusive method is to simply watch after the first soaking rain following a warm dry spell. If the soil is colonized with fungi you can expect mushrooms to sprout everywhere. It’s a wonderful sight to see and an indicator of healthy, fungal dominant soil.

Inspiration for Lewis Carroll’s, ‘Alice in Wonderland’ is often attributed to his alleged use
of LSD, another product of a fungus. On the contrary, I can see where mushrooms, in and of
themselves, with their whimsical shapes, ‘magical’ overnight appearance, and metamorphosis,
could be an inspiration for a fantastical forest world in miniature.

And down the mythical rabbit hole… all of these pictures came from our garden, mostly the
front yard orchard. Also, it bears repeating: Do not eat. Keep away from young children —
especially little brown mushrooms.

What about mushrooms coming out of the stems or trunk of your plant?

Mushrooms coming up out of the ground are a good sign. On the other hand, mushrooms sprouting from the trunk of a tree or from the stems of your plant is a bad sign, indicating that rot is pretty extensive within the plant. It’s not necessarily the fungus that has caused the plant to be infected, but it is a visual indicator that rot is extensive enough that the fungus has reached a point where it feels “comfortable” enough to start reproducing. At this point, the prognosis is not good for your plant, or at least the section of plant that is infected.

Uh oh. Mushrooms growing out of the soil is a good sign signaling fungal dominant soil, but
fungus growing out of the stems or trunk of your plant is a bad thing. The plant is infected with
a fungus. In this case, the rose was long dead from other reasons and the fungus is just doing
a good job of recycling a resource.

This is fine in the bigger picture of Nature reclaiming a sick and weakened plant, but you might not feel fine if it’s one of your favorite plants dying. There are anti-fungal pesticides out there. I’m not recommending them, quite the opposite. But, if it’s a really valuable plant, I would be remiss to not mention they do exist.

For my own plan of action, and what I do recommend, is to concentrate on creating healthy plants and soil conditions. If some plants do succumb to a disease, even with good growing conditions, then perhaps they are not the right plants for my garden. Our goal is resilience and there are plenty of other plants that can thrive in our setting, even with climatic challenges. Plants that need undue attention do not fit our goal for resilience.

In summary, one of the keys to healthy soils is good microbial activity. Fungal soils have a symbiotic relationship with woody plants which creates a system of better health for both organisms. We should follow this example. We should do what we can to encourage soil health and it’s just as important to avoid actions that harm it. What we give to the ecosystem will be returned in kind.

Further Info:


  1. Great article. Question…what about garden beds (or are fungal soils only good for woody plants?)

    1. Hi Ryan. In general, woody plants benefit from fungal soils, whereas vegetables benefit from bacteria-dominated soils. Listen to the Doug Weatherbee podcasts linked to in the ‘Further info’ section at bottom of the article above for more details. They’re a good listen.

  2. Nice – but a little too emotional and you have given the trees human characteristics such as compassion and sociability – trees are fighting each other for survival in the forest not trying to help each other – its survival of the fittest

    1. I feel it maybe yes and no as it is more complex. c Trees that are given enough space for roots to grow are not fighting for anything. Trees that die off are possibly a result of them not receiving enough light as the older trees canopy has obstructed it. However, even those trees can survive, if they are strong enough. Possibly the mycelium super highway helps facilitate that. I am not sure how accurate this description is I was trying to be brief but would be interested in a more complete description.

  3. Hi, when ‘fungal dominated soil’ (as opossedo to ‘bacterial dominated soil’) is mentioned I always wonder whereas it’s saprotrophic, or micorryzic fungi (or a certain ratio) that we are talking about, also How is it measured? In terms of biomass or hyphae lenght?
    I think this is important becouse when fungal dominated soils are to be rised, saprotrophic fungi are always mentioned, but maybe it’s the mycorrizal net which conforms the majority of fungal biomass in forests.

  4. One type of fungi, called mycorrhizal fungi, physically attaches to the roots of woody plants

    Not just woody plants. An estimated 80 % of terrestrial plants including vegetables except for Brassicaceae, have arbuscular mycorrhizal associations during some or all of their life stages. Thousands of studies have tested the physiological effect of mycorrhiza on plants, and many show a positive influence on plant function and fitness; symbiosis with arbuscular mycorrhizal fungi (AMF) is commonly considered to be highly beneficial for plants. The mycorrhizal condition is shown to have wide-ranging effects on host plants, from improved nutrition and stress tolerance to herbivore defense and disease resistance. Fungal hyphae can even act as a means of resource sharing between two otherwise unconnected plants.

  5. Dale,

    I am not so sure that trees are always engaged in a fight for survival. There are quite a lot of studies that demonstrate the “mother tree” effect, as well as the sharing of nutrients, water, and chemical signals between trees. Usually this is the result of the mycorrhizal network. Though it is also true that some species of plants do inter and intra-species root grafting (while others actively avoid such relationships). Look for the work of Suzanne Simard for more research on the “mother tree” concept. A documentary named “Super Fungi” produced in France also covers a lot of this territory (cooperation between species, with an emphasis on the role of fungi).

    Competition and cooperation both exist in nature.

    1. What I was curious about is if you have to prepare soil if you want to introduce mycelium into it, like in raised gardens or roof top gardens?

  6. Vegetable gardens do like fungi present in soil, that’s what no dig is mainly about, creating enviroment for fungi to thrive.
    Beside wood plants, mycorrhizae also works with most veggies we grow, so fungi present in veggie garden soil is essential for plants health, take up of nutrients, water and so on.
    As Craig said, veggies do like bacteria domination in soil, but that doesn’t mean fungi shouldn’t be present, the ratio is simply in favour of bacteria.
    Leafmold is one of the greates mulch for vegetable garden, making good enviroment for fungi and it’s so simple to wotk with in terms of planting and sowing.
    To make soils bacteria dominated simply mulch with bacterial compost, fresh grass etc. along with some leafmold for fungi.

  7. Why do you say “wood chip mulch” ? The real name is “Ramial Chipped Wood” and it is Mr Gilles Lemieux, who reveal the essential rule of mushroom in constituting humus. Using this technic since 2003 in my gardens successfuly in south of France.
    Look at my website!
    Many thanks

  8. I took photographs of 21 different types of fungus in my 2.5 acres of land beside a creek, and showed them to the local DPI rep. He told me that they were negative and that the land was useless…
    Oddly, I had an old hollow tree that housed both a native bee hive AND a European bee hive … living harmoniously together. I did not know then that bees love fungus and derive some benefit from it. They must have loved living on my “useless” land!

    1. Great article James. – trying the same here with very good results.
      Helen – check out Paul Stamets latest findings on Bees and Fungi.

  9. HI James, any idea on the benefits or detriment of using Melaleuca ericifolia wood chips, given it’s a Myrtaceae?
    Cheers mate, great read :)

  10. Is it any wonder why soo many people are dying of cancer & suffering from soo many symptoms of systemic candida? Does anyone actually consider what happens to the bacteria when it leaves our gut & enters the bloodstream & ‘burrows in to our organs’, when we persistently feed it with the foods it likes to eat? I found something very interesting you may wish to have a look. Dr Tulio Simoncini’s website . Also read; ‘The Fungus Link by Doug Hauffmann. Beat Candida Cookbook by Erica White

  11. It looks like the author has gotten symbiotic mycorrhizal fungi confused with decomposing fungi. There are three different feeding strategies in the fungal world– mycorrhizal, saprophytic and parasitic. Mycorrhizal fungi are not decomposers…

  12. i will read this thoroughly, but a question. i live in the northern rockies & my place has several ecozones. i’ve been reading the “hidden life of trees” and the author talks about tree communities, soil, fungi…i have always planted 3 plants, trees whatever at a time…not lost but one…i am happy to have found this site. this is not a question, i guess, but a comment. no need to respond.

  13. What I was curious about is if you have to prepare soil if you want to introduce mycelium into it, like in raised gardens or roof top gardens?

  14. Thanks for that great breakdown! One small thing – LSD was first explored by Albert Hoffman in 1938 and Lewis Carroll wrote Alice in Wonderland in 1865. He may have been tripping but it wasn’t on LSD.

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