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Marin IJ Articles

Love mushrooms? You can grow your own

  • June 1, 2019
  • James Campbell
  • There are more than 86 edible fungi species in the Bay Area. Every mushroom forager knows that mushrooms can kill; the golden rule is to eat only what you can identify. The mushroom responsible for the majority of fatal or otherwise serious mushroom poisonings is Amanita phalloides, the appropriately named Death Cap. Some people don’t really care for the effort involved in hunting for wild edible mushrooms, others would rather be safe than sorry, so most people end up buying mushrooms at the store or farmers market. This year I decided to grow my own.

    Mushrooms can be grown by anyone. They do not require arable or flat land, they have no special light requirements and they do not require large amounts of water. The mushroom lifecycle is shorter than other crops and has a high yield. Due to our cool moist winters, you can grow mushrooms outdoors year-round. Mushrooms also grow indoors easily. I am trying both.

    Basidiomycetes is the class of fungi that produces the mushrooms we eat. Most fungi reproduce asexually by producing spores. The spores are so light they can be carried by the breeze. Interestingly, some mushrooms create their own wind according to UCLA researcher Marcus Roper. The mushroom creates airflow by letting its moisture evaporate. This makes a lot of sense when you consider that many mushrooms grow where the wind couldn’t reach them.

    When spores germinate, they form long filaments called hyphae. When two of the hyphal filaments meet, they form what is known as mycelium. The mycelium will continue to grow and take over the substrate. There are several things that can be used as a substrate. In nature, the substrate is often a dead or dying tree, but the substrate can be straw, sawdust or even corn cobs.

    Once the mycelium has taken over the substrate and environmental conditions are just right, it may form a fruiting body. The fruiting body is what we typically call a mushroom, but there are many types besides just mushrooms. Harvesting a fruiting body does not kill the mycelium. It can continue to grow and live after the fruiting body is harvested. Once the fruiting body matures, it will produce spores starting the whole process again.

    Anyone can grow mushrooms, but that is not to say mushroom growing is easy. I started with the two simplest methods, one indoors and one outdoors.

    Indoors, I am using a mushroom growing kit. It is a plastic bag of substrate that has already been inoculated with spores and has plenty of hyphae forming mycelium. I followed instructions and made a few slits in the side of the bag. I made sure to mist every day until fruiting occurred. The kit came with a separate plastic bag that fits over the bag containing the substrate to create a humidity tent. In about two weeks’ time I had lion’s mane mushroom fruit. It tastes a lot like lobster.

    For my outdoor mushroom farming adventure, I purchased some plug spawn for shiitake and lion’s mane mushrooms. Plug spawn is sterile mycelium growth that has been inoculated into wooden dowels. All you need are some recently cut oak logs with the bark intact. I drilled some holes and then tapped my plug spawn in with a wooden mallet. The last step was to seal the holes with some wax, which is recommended to keep moisture in and bugs out. I found a spot in my garden that is mostly shady and laid the logs on the ground with the side with the plug spawn facing up.

    The shiitake can take as long as a year to fruit but the lion’s mane is much quicker. They should continue producing fruiting bodies for years to come.