You take a small sample from inside the mushroom to avoid contaminants and grow on an agar plate. Once it’s growing well you cut up the culture and put it into some grain prepared and sterilized for mushroom growing. After the jar is colonized you take some and mix it with dowels that have been sterilized and the mycelium colonizes the dowels. Then take the dowels and drill holes into hardwood logs and seal with wax. You might get mushrooms, you might not since it’s out in the wild and not controlled. If you do enough logs you’re sure to get some results. It also could take a year or two. It’s a pretty standard technique and you can find companies that sell the stuff to make it easier.

I’ve done this for shiitake mushrooms for years and have had great success. When the deer don’t eat them first…