If you’re thinking about growing mushrooms, you’ll need to know about something called “mushroom substrate”.
Mushroom substrate can be thought of as shroom fertilizer, something on which the shrooms rely to grow and thrive. But there’s a lot more to it than that.
What is a Mushroom Substrate?
Plants need sunlight to grow. They take carbon dioxide, water, and sunlight from the environment and convert them into the oxygen and carbohydrates they need to grow.
Mushrooms grow in the dark, so they don’t rely on sunlight to get their energy. Instead, fungi draw nutrients from decomposing materials via the mushroom mycelium, which exists underground.
Under the right conditions, the mycelium will produce fruiting bodies that appear above ground. These “fruits” as the mushrooms you see dotted along the forest floor, growing on manure, and popping out of dying tree trunks. They are also the things you harvest when foraging for magic or edible mushrooms.
When growing your own mushrooms, you need to recreate the nutritious environment that leads to the production of those fruiting bodies. This is the mushroom substrate.
What are the Best Mushroom Substrates?
You can grow mushrooms on a variety of substrate materials. The best option is not only the one that provides the greatest yield in the shortest time, but also the one that is easiest to acquire, prepare, and maintain.
You don’t want to be spending too much money on your chosen substrate, either.
Here are some of the best (and worst) options to consider when growing popular magic mushroom species.
Coconut Flour (Coco Coir) and Vermiculite Substrate
This substrate mix is one of the most popular among mushroom growers, as it’s very effective.
Vermiculite is something known as a hydrous phyllosilicate mineral, which means it expands when heated. When used in a substrate mix, it helps with moisture retention.
A mix of 1:1 is usually recommended when using vermiculite and coconut flour, also known as coco coir.
Straw is used to grow many types of mushrooms, including oyster mushrooms. It’s cheap and widely available, but it requires a little more work than other substrates, as it needs to be cut, cleaned, and pasteurized.
You can use 100% straw as a mushroom substrate or blend it with other materials to add more nutrients.
Psilocybe cubensis mushrooms mainly grow on manure, so it can be a good option for mushroom substrates.
But you can’t simply grab some cow dung and then inject your mushroom spores. The manure needs to be composted and then pasteurized to destroy the bad bacteria, making it unsuitable for the average home grower.
Coffee Grounds Substrate
Used coffee grounds are incredibly useful in your garden as they are rich in nitrogen. They have also been recommended in many mushroom substrate recipes. However, there is a high risk of contamination, so they need to be used sparingly.
Brown Rice Flour and Vermiculite Substrate
This mixture works in much the same way as coconut flour and vermiculite. It’s cheap and easy. The substance is typically used in a 2:1 ratio (with two parts vermiculite) and stored in glass jars.
Wood Chips and Hardwood Sawdust Pellets
Hardwood sawdust pellets are a cheap option. They are not very effective when used on their own, but they work really well when mixed with wood chips.
Wood blocks can be used to grow mushrooms, but it’s not the best option for magic mushrooms. You need to find a species that will actually feed on wood and then make sure that you have the right wood. It can be impractical and expensive, and there are better options out there.
Cardboard and Coffee Grounds
You can use just cardboard to grow oyster mushrooms and some mushrooms work really well in a mixture of cardboard and coffee grounds. For magic mushrooms, however, you will struggle to get anything to grow on cardboard.
How Do You Make A Mushroom Substrate?
The first step to making mushroom substrates is pasteurization/sterilization.
Mushroom substrate sterilization removes all the harmful microbes, ensuring they don’t damage or compete with your mushrooms. If you’re using organic material, there will be a lot of bacteria and microbes in there, and you could find yourself harvesting all kinds of nasty things along with your mushrooms.
Sterilization involves subjecting your mushroom substrate to heat of at least 120 °C (248°F). This should be enough to kill all living or dormant contaminants in the substrate.
Pasteurization is similar but less effective. It entails heating the substrate to between 65 and 85 °C (149 to 185°F) and holding it there for a few hours. It should be enough to kill most harmful bacteria and give your mushrooms the best chance.
Always prepare mushroom substrates in this manner to avoid any unfortunate incidents further down the line.
Can You Use Soil As Mushroom Substrate?
You can’t use standard soil to grow mushrooms. They don’t grow like plants and require very specific nutrients and conditions.
What Is Substrate In Mushroom Cultivation?
Substrate is essentially a decomposing fertilizer that’s used to produce mushrooms. It is used for both edible mushrooms and psychedelic mushrooms, though the best materials can vary significantly by species.
Do I Need a Substrate if I Have a Grow Kit?
All grow kits come with a suitable substrate. Just follow the instructions on the kit to activate it and start growing those shrooms.
What Can I Do With Spent Mushroom Substrate?
You can add spent substrate to your compost pile, where it will likely produce another flush of mushrooms. You could also use it to produce more mushrooms, but it depends on what type of substrate you use and what condition it’s in.
Summary: Mushroom Substrates
There is no one-size-fits-all solution when it comes to mushrooms. There are many species of mushrooms out there and they all thrive in varying conditions, and that’s true whether you’re sticking with nutritional and delicious fungi like oyster mushrooms or opting for something more psychedelic.
But if you stick with an affordable and easily acquired substrate and prepare to experiment, you will eventually find the one that works best for you.