What is a Mushroom Substrate and Which is the Best?

If you are interested in mushroom growing, it is vital to know the significance of mushroom substrates.  Getting the right substrate recipe is an essential aspect of mushroom cultivation.

Before we go further, it is essential to know that a mushroom is not a plant but a fungus and all mushrooms are fungi but not all fungi are considered mushrooms.  If you want to grow mushrooms, it is important to learn the basic anatomy of a fungus.

If you compare the mushroom to a plant, the mushroom can either be the flower or the fruit.  When the plants have roots that are responsible for reaching out to a food source so the plant can survive, the mushroom has mycelium.  The mycelium connects the fungus to its food source for the mushroom to grow, and the mycelium is the vegetative part of the fungus that produces mushrooms.

What is a Substrate?

The substrate is the source of food for fungi.  Note that the roots of a plant get food from the soil – which is the primary food source for the plant. Fungus, on the other hand, connects mycelium to the substrate to get food.  The substrate is the primary source of food for fungi so they can produce mushrooms.

Now, let’s concentrate on the substrates.  When growing mushrooms, you will be putting the mycelium into its food source, which is the substrate.  This process is called inoculation to induce the growth of mushrooms.  The substrate serves as the organic host and the mycelium as parasites that depend on the substrate for food.  The ability of the fungi to breed mushrooms depends on the kind of substrate hosting the mycelium.  This is why the preparation of the substrate is vital to your mushroom growing.

A substrate can be any material on which mycelium can grow.  Many different materials like straw, logs, grains, coffee granules, and many others can be considered a substrate.

A substrate is inoculated with mycelium using a mushroom spawn.  A spawn is a small quantity of a nutritious material upon which the mycelium can start to grow before it begins to colonize a substrate.

Types of Mushroom Substrates

Here are some of the substrates you can use to grow mushrooms.

Straw

Straws of cereals like wheat, oat, and rye can be an excellent base for mushroom growth as they are always available and inexpensive, The use of straw can be advantageous as it can be used in growing many different types of mushrooms.  Many mushrooms find it easy to break down fibers of straw.  One disadvantage though is that you need to prepare the straw before using it.  So if you are growing mushrooms especially indoors, you must make sure that you get rid of the tiny microorganisms that are usually present in the straw. Otherwise, they will be competing with the mycelium for the food source and there is a great chance that the mycelium won’t grow.

There are many ways to treat the straw, and one of them is through the process called pasteurization or sterilizing through heat.

Logs

Logs can be used to grow mushrooms.  It is cut, inoculated with dowel spawns, and left to incubate.  However, in your choice of logs to use, you must take into account the same kind of wood that your type of mushrooms grows on naturally.  Therefore, it is best that you must first research the type of mushroom you want to grow to maximize success.

Generally, any hardwood that’s not too dense and quick to decompose will do such as elm, ash, alder, cottonwood, and beech.  Hardwoods like oak will keep longer to produce mushrooms.

Enriched Sawdust

Most often, commercial cultivators are using enriched sawdust.  This substrate works well with different varieties of mushrooms, but there are still some things to consider when using it.

The first thing you need to think of is the kind of sawdust you are going to use.  Sawdust that comes from hardwood is good, but make sure that the sawdust is not too fine because it tends to pack too densely and deprive the mycelium of air.

Another thing that you again need to consider is the fact that the sawdust lacks the proper nutrient requirement and therefore need to be enriched with nitrogen supplement such as bran.  Using nutrient-enriched sawdust will result in a higher yield compared to using plain sawdust.

Furthermore, sawdust is also a host to microscopic competitors that it needs to be sterilized before using it, and this requires specialized equipment such as an autoclave.

Other Substrates to Use in Mushroom Growing

There is an unlimited list of substrates you can use, and here are some others that are proven to be effective:

  • Compost
  • Used organic coffee grounds
  • Used organic tea leaves
  • Cardboard (without toxic dyes)
  • Papers and other paper produce (without toxic inks)
  • Stumps
  • Gardening residues and debris
  • Other organic materials including corncobs, seeds, shells, and banana leaves.

The Best Mushroom Substrate

When choosing the best type of substrate for your mushroom-growing project, make sure it is a match to the spawn you will be using.

So, if you want to grow mushrooms on logs, it is best to use a wood-based spawn like sawdust or plugs.  If the mycelium is already familiar with the spawning material, the time for colonization is reduced.

Also, you need to consider the types of mushrooms that you want to cultivate.  Mushrooms like reishi, lion’s mane, and maitake are best on wood-based substrates while other varieties like oysters thrive on almost any substrate.

Here is a list of complimenting substrates and spawns.

  • Grain – indoor bags of enriched sawdust and pasteurized straw
  • Sawdust – wood-based substrates like logs, enriched sawdust, wood chips, cardboard, and outdoor straw beds.
  • Dowel/Plug – logs and wood chips

If budget is a limiting factor in your choices, you can always look around for different materials to use as a substrate.  Look around your property or go to the woods.  You may find some stumps or logs that you can use for free, or you may save tea leaves and coffee grounds for mushroom growing materials.

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