How to grow oyster mushrooms

If you like mushrooms and want to grow your own, oyster mushrooms may be your best choice. Knowing how to grow them can bring you an almost unlimited supply and, although they grow on trees by nature, oyster mushrooms thrive on nearly all kinds of agricultural waste.

Oyster mushrooms have a rich culinary and medicinal history and, when grown by yourselves, are free of pesticides and other chemicals used to make them presentable and improve their shelf life. They are high in potassium, iron, zinc, vitamin C, calcium, niacin, phosphorus, vitamins B1 and B2, and folic acid, improve the body's immune system, lower cholesterol levels and are one of the very few organisms containing ergothioneine which is a powerful antioxidant.

The easiest way to grow oystermushrooms is by buying a ready to use mushroom kit. Another way is to use a small mushroom kit as spawn and mix it with a considerably larger amount of straw or sawdust, thereby multiplying your harvest several times. The third method is the cheapest and involves producing your own oyster spawn. This can be easily done by laying a few pieces of stem tissue from store bought mushrooms on sterilized cardboard. Within a few days the tissue clones will start growing again and will quickly colonize the cardboard.

Once the cardboard has been fully colonized with the oyster mycelium it's time to apply a thin layer of used coffee grounds onto the cardboard. The coffee grounds should be as fresh as possible and have to be squeezed out to field capacity. The applied layer of coffee grounds shouldn't be thicker than 1 inch at the most. A thin layer will be colonized faster and will minimize the risk of contaminations by mold spores from the surrounding air. Once the coffee grounds are colonized a second layer can be applied. Keep applying new layers until the jar is filled to about 1 inch below the rim. The spawn can then be used to inoculate bulk substrates like straw or sawdust.

Oyster mushrooms thrive on a wide variety of substrates. Straw and sawdust are most common but they can also grow an coffee gounds, coffee filters (see picture of a 1 gallon bag with a mix of spawn and used coffee filters) or even cardboard (be careful-cardboard might contain poisonous constituents). Mix the spawn in a ratio of 1 part spawn to 1-4 parts of bulk substrate. More spawn means quicker colonization and a lesser risk of contaminations. Use any container you like and that is not to small. Containers with a capacity of 1 gallon or more are fine. Containers deeper than 8 inches need a few holes in the sides, so that the mycelium gets enough air to breathe.

It's a simple as that. Make sure not to use up all spawn, but multiply it and use it for your next mushroom kit. Eventually, after a few months or longer, the mycelium will get old, will start to degenerate and produce lower yields of mushrooms. If that happens you have to buy new oyster mushrooms and start all over again.