Mycorrhizae fungus is a Mother Nature natural product, the result of plant litter falling to the ground year after year and cold composting. The roots of those plants, shrubs and trees that utilize MF reach their feeder roots upward toward soil surface seeking it.

3 methods for the home gardener to make homemade Mycorrhizae:

1. In vegetable gardens- Read the writings and incorporate the gardening methods of Ruth Stout. Simple. Use hay or straw as a mulch. Never move it except to plant a row or dig a hole. Add all vegetable clippings to the mulch. Repeat year after year allowing it to cold compost and make all those varieties of MF needed for verdant veggie growth. It sounds as though you have already adopted this method. Doubtful that mushroom growth will add anything to your present mix.

2. In flower and shrub type gardens. Every fall rake and shred all leaves, woody clippings, etc. associated with those types of gardens and return the shreddings as mulch to the gardens to cold compost.

3. Every year rake and shred fallen leaves. Set aside an out-of-the-way spot where these shredded leaves can be smoothed into a pile no higher than 5" (inches) and allowed to cold compost. Grass clippings can also be added to the mix.
It helps to outline this spot with tree trunks or sections of wood. When MF is needed to add to a planting project, reach beneath this leaf pile and gently scrape along soil surface which, after a few years, should be ready for use. MF is fragile, so handle these soils gently.

SOME, but not all, mushrooms are the fruiting bodies of Mycorrhizae that have symbiotic relationships with plants. (eg chanterelles and porcini are). Other kinds of mushrooms grow on dead plant matter. (eg the button mushrooms from the supermarket...)

Studies have shown commercially packaged Mycorrhizae are beneficial to plants growing in mine tailings but offer no detectable benefits under normal circumstances. If plants have been growing on a spot for a couple decades and it's been a couple decades since the spot has been plowed, all the right Mycorrhizae have probably found their way there already.

For trees and undomesticated native plants, the absolute "gold standard" for Mycorrhizae is soil from a spot in the forest where that plant grows well. That will have the Mycorrhizae that this particular plant has a relationship with.

Commercial products are kind of guessing what Mycorrhizae are best, and even if they guess well the ones they pick may not be the ones your particular plants use. (Different plants use different species of Mycorrhizae.) I also suspect they are also probably influenced by what kinds of Mycorrhizae can be artificially mass produced and can survive in a bag on a store shelf.

As far as how it travels in nature...when two fungus love each other very much (and happen to be growing next to each other) their hyphae meet and make a mushroom. The Mushroom contains DNA from both, and produces spores from the gills at the bottom. (Or burst open and releases spores) The wind carries these spores.

As for what you can do...
1.) Take shovels full of dirt from near your favorite edible mushrooms and near old or wild specimens of plants you are growing in your raised bed. Then pour them in the plating hole when you plant new ones in the raised bed.
2.) If you see an edible mushroom you like, look to see if there are still spores in the gills. If there are, blow them in the planting holes or mix them with compost. (Or better yet, mix them in manure. Grow mushrooms in the manure in your basement, then use the manure as fertilizer).

Although honestly, if you have a healthy mushroom population in your yard, they will probably find their way into your raised beds on their own.

This post was edited by edlincoln on Thu, Nov 13, 14 at 20:42

i had bought a bag of shitake.
i forgot to put them in the refrig, and they went bad
so, i put them in a blender with water, and poured it over a few areas of my yard with lots of leaf litter.
i get 80lb of coffee grounds at a time from Starbucks,
i also get several large bags of grass and leaves every week in the summer and fall, so, my "mulch" is 2 ft deep in spots.
waiting for shrooms :)

i have to think even if i dont get shrooms, it will be good for fruit trees etc...
i have a lot of leaves and UCG they will much on, and degrade.

i also create a bucket of microbes 2-3 times per year.
i take a handful of compost, one of worm castings (live)
throw them in a 5 gal bucket with molasses, cane syrup, protien powder (that went bad), and a spoon of MFungi

aerate for 2 days

supposedly Mychorizal Fungi only activate in the presence of roots, so, i put roots of 5 different plants (weeds mostly)
in a blender and added that too. (with some of the dirt)

I have never read Ruth Stout although now I may have to. I tend to compost/mulch/build/younameit with straw and even hay bales as they are a cheap and readily available source of OM where I live. I like to leave them out in the elements to decompose for at least a year before mulching. I've noticed in wet years (or every year if your climate is wetter than mine) that straw bales will be popping with shrooms. If you break the bale down, you'll find that wonderful white substance called mycelium. This is the main body of the mushroom, as opposed to the actual "mushrooms", which are just flowers. Whenever I find this I put it face down on top of the soil, and mulch super heavily on top of that. I don't know that this has produced any symbiotic relationships, but then again, at the time I was gardening in a fairly dry climate. I never did have mushrooms pop out of the mulch. I guess only the insides of a bale stayed moist enough. I think maybe next spring in my new garden I'll try adding a little to planting holes so they are "in the presence of roots" and see what happens.

Long story short, if you leave straw bales out in the sun and rain you'll have mushrooms before long. THEY MAY BE POISONOUS. I'm not saying that as a general warning...there are some quite poisonous mushrooms that love decaying straw. Don't eat anything you find growing out of a straw bale. Also keep in mind that the power of mushrooms is not limited to symbiosis. They chew through organic matter at an insane rate, and finished mushroom compost is wonderful for your plants regardless of colonization. If you can't innoculate your garden, try innoculating your compost pile!

there are 10s of thousands of types of organisms in a teaspoon of soil. not total organisms (those are in the billions) but, individual species... you want as diverse a set as possible. so getting a handful of soil from the forest floor, or and undeveloped area is the best thing.

using wood chip mulch promotes fungal growth.

mushrooms "flower" or, produce the fruiting body when they run out of food. so, dont forget to feed the soil. i like using fish hydrolysate , and molasses. Kelp and other seaweeds are great as well. all have tons of minerals and nutrients.

fish hydrolysate is different than fish emulsion. fish hydrolysate is made from a cold process, and has more oils and living enzymes.

sugars will make your soil more bacterialy dominant. better for veggies, but weeds grow also.

high carbon will make the soil more fungal. this better for fruit trees

another way to say this...

Perennial plant systems trend more toward acidity and fungal dominance and annual plant systems trend toward alkaline and bacterial dominant soils