HOW TO CHOOSE THE BEST MUSHROOM GROWING SUBSTRATE

When it comes to cultivating mushrooms successfully, choosing the right substrate plays a vital role. The substrate serves as the foundation upon which your mushrooms will flourish, making it a decision not to be taken lightly. This guide will walk you through the essential steps to select the best mushroom substrate for your cultivation journey. 

Understanding Mushroom Substrate

At its core, a mushroom substrate is akin to the soil for plants. It’s the substance on which mushrooms grow, deriving their nutrients from it. However, unlike most plants, mushrooms don’t perform photosynthesis. Instead, they decompose and convert organic material into the nutrients they need for growth. This is where the substrate comes into play. 

A good substrate is rich in organic matter. Common ingredients include straw, wood chips, grains, manure, and even coffee grounds. The exact mix often depends on the species of mushroom being cultivated. For instance, oyster mushrooms thrive on straw, while shiitake mushrooms prefer hardwood. More on that later! 

Preparing the substrate is a crucial step. This often involves pasteurisation or sterilisation to kill unwanted bacteria and contaminants. This ensures that the mushrooms have an optimal environment free from competition. 

In essence, a mushroom substrate is both the foundation and the food source for the mushrooms. A good substrate nurtures the mycelium (the root system of mushrooms) and provides the necessary nutrients for mushrooms to fruit and thrive. 

If you’re a hobbyist looking to grow your own edible mushrooms at home, understanding the role of the substrate is key to appreciating the intricate dance of fungal growth! 

Considerations for Substrate Selection

When choosing the best substrate for your mushroom cultivation, several factors come into play: 

1. Mushroom Species 

Different mushroom species have specific substrate requirements. It is very important to research and identify the species you wish to grow, as this will dictate the appropriate substrate type. 

2. Nutrient Content 

A crucial aspect of substrate selection is its nutrient content. The substrate must provide the necessary nutrients for the mushrooms to thrive. 

3. Sterilisation/Pasteurisation

To prevent contamination and ensure a healthy growing environment, the substrate must undergo sterilization or pasteurization, depending on the chosen method. If you want a more detailed guide about Pasteurisation vs. Sterilisation, you can check it here (link).

4. Water Holding Capacity

The substrate’s ability to hold water is vital for mushroom development. It should strike a balance between retaining moisture and allowing proper aeration. For most types of substrate, the ideal hydration is between 60-70% water content.

4. Availability and Cost 

Consider the availability and cost of the substrate material. Some substrates, like spent coffee grounds, may be more readily accessible and cost-effective than others. 

Selecting the Ideal Mushroom Substrate

Selecting the appropriate substrate is essential for achieving successful mushroom growing. Various factors come into play, such as the mushroom species you intend to grow, the availability of materials, and the desired yield. Let’s explore some of the most popular and effective mushroom substrates:

1. Manure-Based Compost 

Manure-based compost is a good substrate for growing mushrooms because it is high in nutrients and provides a good environment for mushroom growth. However, it is important to use manure that has been properly composted to kill any harmful bacteria or mold.
2. Spent Coffee Grounds 

Using spent coffee grounds as a nutrient-rich medium is a fantastic choice for cultivating gourmet mushrooms. However, it’s essential to be cautious, as some coffee grounds may contain harmful bacteria or mold. To ensure safety, opt for coffee grounds that have been composted or sterilized before use.

3. Straw 

Straw stands out as an excellent substrate for numerous mushroom species, including the beloved oyster mushrooms. Not only is it affordable, but it’s also readily available and easy to prepare. The balanced levels of carbon and nitrogen make it an ideal choice for mushroom cultivation. 

4. Sawdust

Straw stands out as an excellent substrate for numerous mushroom species, including the beloved oyster mushrooms. Not only is it affordable, but it’s also readily available and easy to prepare. The balanced levels of carbon and nitrogen make it an ideal choice for mushroom cultivation.

5. Wood Chips 

To create wood chips substrate, wood is chipped into small pieces, offering a nutrient-packed option for growing mushrooms. Additionally, it helps to retain moisture in the substrate, enhancing the growing environment. For optimal results, blend it with other ingredients like straw, hardwood sawdust, or coco coir, with the ratio depending on the mushroom type being cultivated. 

6. Soybean Hull 

Soybean hull substrate is well-suited for those that thrive on a high-nitrogen diet, such as oyster and shiitake mushrooms. Just like with wood chips, you can combine soybean hulls with straw, hardwood sawdust, or coco coir to create a balanced and nutritious environment for mushroom growth. 

7. Gypsum 

Gypsum is another beneficial substance used in mushroom growing. It contains calcium sulfate dihydrate, providing essential nutrients like calcium and sulfur for mushroom growth. To use gypsum as a substrate, mix it with other ingredients like straw, hardwood sawdust, or coco coir in varying ratios depending on the mushroom species. 

8. Coco Coir 

Coco coir is a natural and organic substrate derived from the fibrous husk of coconuts. It serves as an excellent nutrient source for mushrooms and is highly absorbent, promoting moisture retention in the substrate. This makes it an ideal choice for mushrooms that thrive on a high-fiber diet, such as oyster and shiitake mushrooms. 

9. Vermiculite 

Vermiculite is a lightweight and porous material made from heated mica. It offers essential nutrients for mushrooms and aids in maintaining the necessary moisture levels in the substrate. For mushrooms that prefer a high-moisture environment, like oyster and shiitake mushrooms, mix vermiculite with other ingredients like straw, hardwood sawdust, or coco coir.

Popular Types of Mushroom Substrate for Different Species 


Choosing the best combination of substrates depends on the type of mushrooms you wish to grow. Here are some of the most popular substrate blends for different mushroom varieties: 

1. Oyster Mushrooms (Pleurotus species) substrate 

Straw: Provides structure and bulk to the substrate. 

Sawdust: Enhances nutrient content and moisture retention. 

Gypsum: Balances pH levels and prevents clumping.  

 2. Shiitake Mushrooms (Lentinula edodes) 

Hardwood Sawdust: Ideal for shiitake mycelium growth. 

Bran: Adds extra nutrients to support fruiting. 

Calcium Carbonate: Maintains pH stability 

3. Lion's Mane Mushrooms (Hericium erinaceus) 

Oak (or other hardwood) Pellets: Provides additional nutrients and structure. 

Soybean Hulls: Improves water retention.  


4. Exotic or Dung Loving Mushrooms 

Coco coir: A good source of nutrients and help to retain moisture 

Vermiculite: Provides aeration and water retention

Gypsum: Maintains pH stability and aeration of the substrate  


 

 

Blended Substrate vs. Single Substrate: Which is the Best Choice for Mushroom Growing?


When it comes to choosing the ideal substrate for growing mushrooms, there’s no one-size-fits-all answer. The decision hinges on various factors and what suits each grower’s specific needs and goals. Let’s delve into some key considerations to help you make a well-informed choice:  

1. Scale of Cultivation 


If you’re a commercial grower aiming for substantial mushroom production, mixed substrates might be the way to go. They offer scalability and efficiency, allowing you to meet higher demands. However, for hobbyists or small-scale growers, single substrates can be more manageable and cost-effective, catering to their scale of operation. 


2. Mushroom Species 

Different mushroom species have their own preferences when it comes to substrates. It’s crucial to research the requirements of the specific species you wish to cultivate. This knowledge will help you identify the substrate that best aligns with their needs, ensuring better growth and yields. 

3. Contamination Risk 

Contamination can be a significant concern depending on your region or growing environment. In such cases, mixed substrates might present a more viable option. By combining multiple substrates, you can reduce the risk of contamination and mitigate potential losses, safeguarding your mushroom crop. 


4. Experimentation and Experience 

Seasoned growers often enjoy experimenting with mixed substrates, leveraging their expertise to fine-tune the growing process for optimal results. Their experience allows them to innovate and discover new ways to boost mushroom growth and quality. 

Conclusion

If you are a beginner in mushroom growing, you need to figure out which is the best mushroom substrate for your desired mushroom species. It is very important to use natural and organic ingredients for your substrate. By selecting the right substrate and providing the appropriate conditions for growth, you can achieve bountiful harvests of high-quality mushrooms. 

Have questions about mushroom substrates? Contact our mycologists! Click here.