A mushroom substrate is the material in which fungal mycelium grows and thrives. It provides the “food” (nutrients, moisture, energy) required to produce mushrooms. Growers use many different types of substrates, typically sourced from low-cost agricultural byproducts like hardwood sawdust, straw, wood chips, and compost, depending on the individual preferences of each mushroom species. Choosing the right substrate is a key step for any mushroom farmer, whether you're new to cultivation or an experienced grower looking to improve your yields and quality. One of the most versatile and beginner-friendly options for growing indoors is the CVG substrate; a blend of coco coir, vermiculite, and gypsum. Our CVG is designed to make the process simple, reliable, and efficient for growers at any skill level. Let’s explore how to make the most of this substrate and why it’s a solid choice for your mushroom-growing journey.
What is CVG?
CVG stands for “Coir, Vermiculite, and Gypsum,” a mixture that has become a popular choice among home growers and small-scale cultivators. This mix is known for its simplicity, affordability, and ability to support different mushroom varieties, including edible mushrooms like Oyster mushrooms and medicinal dung-loving species. Each component plays an essential role:
What is coco coir?
Derived from coconut husks, coir is a lightweight, contamination-resistant substrate and known for its excellent water retention, crucial for maintaining moisture levels.
What is vermiculite?
Vermiculite is a mineral that improves aeration and holds moisture, helping distribute water evenly throughout the substrate.
What is gypsum?
Gypsum is a calcium-rich mineral that acts as a pH stabilizer and provides essential nutrients for healthy mycelial growth. We utilize a pelletized form, which improves subtrate structure, reduces compaction, and increases water retention.
Which mushrooms can I grow with CVG?
Decades of trial and error led mycologists and mushroom cultivators to develop CVG for growing medicinal dung-loving mushrooms as well as a variety of gourmet edible species including Blue Oyster, Lion’s Mane and Pioppino mushrooms. CVG is versatile enough for both culinary species as well as dung-loving species.
Why choose CVG for mushroom cultivation?
✔ Easy & Ready-to-Use: Our CVG substrate comes pre-sterilized and ready to use as a bulk substrate for growing mushrooms. If you choose to purchase coco coir, vermiculite, and gypsum separately, they’ll need to be mixed, hydrated, and pasteurized before use. Preparing the substrate doesn’t require complex sterilization methods. Pasteurizing the mixture with hot water is sufficient, making it a beginner-friendly option that avoids the need for specialized equipment.
✔ Nutrient Support: While coco coir and vermiculite are great for moisture retention and structure, gypsum adds minerals and trace elements that encourage robust mycelial colonization and increased yields. Gypsum has also been found to help mushroom substrates resist pH fluctuations that can increase contamination potential.
✔ Dependable Results: CVG substrates have been helping beginner growers for years, yielding consistent flushes with low risk for contamination.
CVG Monotub Kit: ideal for beginners
Our new CVG Monotub Kit is perfect for newcomers to mushroom cultivation. This kit includes:
A Boomr Bin monotub & self-adhesive filters: A patent-pending, food-grade container optimized for manual or automated mushroom growing. The filters ensure proper gas exchange while keeping out contaminants.
Two CVG Sterile Bulk Substrate (5 lbs each): A ready-to-use mix hydrated and sterilized for consistent growth.
An Organic Sterilized Grain Bag (3 lbs): With an injection port for easy inoculation.
A Myco Coco Coir casing layer (1 brick): Adds moisture retention and helps maintain optimal pH.
Advantages of the CVG monotub kit
✔ Higher Inoculation Rates: Using less substrate (2 bags instead of 3) helps beginners achieve faster colonization and reduces contamination risk.
✔ Modular Monotub: The Boomr Bin is designed for easy cleaning and adaptable upgrades, such as air exchange and humidification systems.
✔ Beginner-Friendly Preparation: With the kit's sterile components and simplified process, new growers can avoid contamination that more nutrient-rich substrates may attract.
How to grow mushrooms with CVG
1. Inoculation: Mix grain spawn evenly into the prepared CVG substrate to speed up colonization.
2. Incubation: Keep the substrate in a warm, dark space (65–77°F/18–25°C) for 1–3 weeks.
3. Add a Casing Layer: Once fully colonized, top the substrate with ¼ in to ½ in of Myco Coco. This casing layer reduces the potential for contamination and aids in moisture retention in the substrate.
4. Fruiting: Once fully colonized, introduce light, fresh air exchange (FAE), and humidity to promote mushroom growth.
5. Subsequent Fruitings: CVG monotubs can produce multiple flushes with proper care. To encourage a second flush, spray the substrate heavily with clean water and reseal the tub. For a third flush, submerge the substrate block in water for up to 12 hours, then drain thoroughly before returning it to incubation conditions. Avoid over-saturating the substrate after the first flush.
CVG vs. Boomr Bag
Choosing between CVG and our manure-based substrate Boomr Bag depends on your budget, your comfort with contamination risk, and your overall yield goals. CVG offers a straightforward substrate with fewer ingredients at a lower price point that is easier to handle and has a lower risk of contamination. The Boomr Bag, designed for dung-loving mushroom species and crafted by mycologists to maximize yield, is a nutrient-rich blend of composted horse manure and coco coir along with proprietary supplements. Both provide excellent aeration, hydration, and moisture retention that works well for indoor monotub setups, filter bags, trays, and grow rooms.
Final thoughts
Our CVG substrate and CVG Monotub Kit simplify the cultivation process, making it accessible for beginners and rewarding for experienced growers. Its consistent water retention and resistance to contamination offer an excellent foundation for mushroom growing. For those ready to expand their growing operations, moving to more advanced setups like Boomr Bag substrates is a natural next step.