If you’ve never heard of mycorrhizal fungi you may be wondering why on earth you would want to make your own. After all, most types of fungi are problematic. But mycorrhizal fungi supply plants with all sorts of nutrients and also increase the availability of water.
You are going to need a host plant to make your own mycorrhizal fungi. There are two ways to do this, either with a trap culture method or by making your own fungi from a soil sample. But the easiest way to make homemade mycorrhizal fungi is by harvesting the root area of a plant that is already infected.
What are mycorrhizae?
Mycorrhizal fungi are a very common group of fungi that live in the soil. They “infect” the roots of most plants but they are not a parasite or pests.
A simplistic explanation is that mycorrhizal fungi form large networks of fine filaments that grow through the soil around the roots of plants. While they aren’t roots, they act in a very similar way to roots, collecting water and nutrients for plants.
In return, plants send sugars from their leaves to the fungi to feed on.
There are several types of mycorrhiza, but the most common type is arbuscular mycorrhiza (AM). Like other types of this fungus, you aren’t going to see it with the naked eye, but it forms a fine mesh through the soil.
The benefit of mycorrhizae is that they supply nutrients to plants through the fine mesh they form. These include copper, phosphorus, and zinc.
The plants, in turn, support the fungus with carbon, in the form of sugars. It’s a symbiotic relationship that doesn’t affect plants because they produce excess carbon.
The most important factor is that plants with mycorrhizae typically grow faster and a lot bigger because of the increased nutrients they get fed through their roots.
The beauty of this particular fungi type is that it is found occurring naturally in healthy soil. So, it’s not difficult to harvest the spores and make your own beneficial fungi soil.
Are there different types of mycorrhizae?
There are two different types of mycorrhizae that are classified as ectomycorrhizae and endomycorrhizae. Ectomycorrhizae penetrate the cells of the plant roots, while endomycorrhizae don’t.
Basically, certain coniferous and American hardwood trees, including beech, birch, chestnut, hickory, and oaks are associated with ectomycorrhizae. They only pair with about 10% of plant families.
Most vegetables, shrubs, grass, and other trees are associated with endomycorrhizae, as is cannabis. Endomycorrhizal fungi form symbiotic relationships with about 85% of plant families. They pair well with leafy greens and many fruiting or flowering plants.
How are mycorrhizae made?
AM fungi are able to reproduce in many different ways, through colonized root pieces, hyphae, and spores. Numerous studies show that the application processes for reproducing the fungi vary depending on which parts you use.
In ideal conditions, it is possible to colonize roots in 5-16 days. However, it can take more than four months to encompass the entire root system of a plant.
The caveat is that different species of mycorrhizae exist in different soils. So, many experts advise against buying manufactured types because they might end up inhibiting, rather than encouraging, the growth of your plants.
The Rodale Institute in the east of Pennsylvania has loads of information about how mycorrhizae are made. As they say, viable mycorrhizal hyphae, mycorrhizal spores, and pieces of colonized crop roots may all be used as inoculum to “infect” other plants with AM fungi.
Suitable host plants must be from a different family than the crop that is already inoculated. So, if you are looking for a fungus that will target vegetables, something like bahiagrass will be an ideal host plant.
The problem is that bahiagrass isn’t available commercially, so farmers generally need to start their own seeds. But if you are a home gardener who wants to make your own mycorrhizal fungi, what is a simple method that you can use?
How to make homemade mycorrhizal fungi
You can propagate AM fungi with a host plant and this can be any type of plant that supports endomycorrhizal colonization. Since at least 80% of land plants support AM fungi, it shouldn’t be difficult to start the process.
But remember that you will need homemade mycorrhizal fungi that will penetrate the cells of your plants’ roots.
A legendary U.S. gardener, Ruth Stout, who was born in the mid-19th century (1844), tried to imitate the ways that nature created fertile soil. One of the methods she developed was how to make mycorrhizal fungi.
All she did was use straw and hay as mulch and add vegetable clippings to this. She let it be and simply dug holes where she wanted to grow new plants.
But is it really that simple? It worked for her, but this is what most gardeners do today.
Simple DIY methods to make homemade mycorrhizal fungi
There are two ways to make your own mycorrhizal fungi. You can either use a trap culture method that will multiply a commercial mycorrhizal inoculum or you can make your own AM fungi from a starter soil sample.
Of course, the cheapest method is to make your own fungi.
The first step will be to find a mycorrhizal fungi host and dig out some starter soil. Unfortunately, it’s not that easy to ID a host, but if you get it right you’re on the right road.
Remember that they are present in more than 80% of plant root systems and you will find them in the so-called middle zone of soil around the root system. So give it a go.
Ideally, the soil won’t have been cultivated because digging and moving the soil will kill fungi mycorrhizal. So, look for plants that are likely to have these beneficial fungi growing around their roots. If there are mushrooms growing there, that will be a bonus.
Usually, the fungi mycorrhizal host that you need will be in the top three inches of soil. But you need to make sure that the volume of roots to soil is at least 50%.
Dig up the root balls and shake off the soil carefully so that you don’t get rid of the valuable hyphae. Then cut up the root system using scissors and mix it into the start soil (inoculum).
The other way is to mix a starter mycorrhizal inoculum with sterilized coarse sand 1:1 and put it into a pot. Then overseed the pot with Bahiagrass or some other seed.
You can grow the seed outdoors or in a greenhouse but it’s going to take about four months.
Maintaining your mycorrhizal fungi
Your mycorrhizal fungi inoculant will continue to grow and there’s not a lot you need to do. Just don’t mess with it.
Once it gets going, it’s going to multiply, and you can reap the benefits.
Mycorrhizal fungi might be the best thing you’ve used since the best organic fertilizers your mother told you about. But we admit that they are not the easiest nutrients to make yourself.
Still, our garden tips will give you some pointers if you want to take the challenge. If you go for it, let us know how you fare.