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DIY Mushroom Soil: The Ultimate Guide!

Updated: Jan 6, 2023

Welcome to our tutorial on how to make your own mushroom soil using coco coir, vermiculite, and water. If you're an avid fungi gardener or just looking to start your own indoor mushroom garden, having a good quality soil mix is crucial for the success of your happy little fungi. While you can certainly purchase pre-made soil mixes in our online gardening store, it can be more economical and customizable to create your own mix at home.

This particular soil mix is designed to work with our 3-Step Mushroom Grow Guide. Pick up a copy for yourself for free here!

In this post, we'll walk you through the 3-steps on how to make your own mushroom soil using coco coir, vermiculite, and water – ingredients that are widely available and provide a range of benefits for mushrooms and fungi. We'll also discuss the benefits of using these specific ingredients and provide some tips on how to properly care for your soil mix. So let's get started on creating the perfect soil mix for your plants!

Step 1: Gather supplies

Some of these ingredients you likely have just laying around your house or workshop. Others, you might have to get on Amazon! And, of course, you can purchase the coco coir, pre-measured vermiculite, and gusseted poly bags in our store.

Some items such as the additional 5-gallon bucket without a lid or the 16-quart cooler, or the submersible thermometer are just recommendations to make your life a lot easier! Choose what works best for you.

You’ll need the following:

Step 2: Mix material

  1. Use your 5-quart pot and submersible thermometer to bring the 4 liters of water to 71 degrees Celsius.

  2. While the water is coming to temperature, place the split brick of coco coir in the bottom of the bucket with the screw-top lid. Spread the vermiculite on either side of the brick so that it helps the brick stand on its long side.

  3. Carefully pour the water over the brick and the vermiculite.

  4. Screw the lid onto the 5-gallon bucket.

  5. Wait 2 minutes.

  6. While you wait, place the gusseted poly bag inside the 2nd 5-gallon bucket.

  7. Open the bucket and gently mix the material with your drill and paint mixer. It’s important not to overmix. Typically, we recommend mixing for no more than 10-15 seconds.

  8. Carefully dump the contents of the bucket into the 2nd bucket.

  9. Pull the bag with the soil out and loosely twist or fold it. It’s important to keep the flap somewhat open to allow some steam to escape.

  10. Place inside the cooler with the opening of the plastic bag kept upright. This will prevent water from spilling into your cooler.

Step 3: Pasteurize for 24 hours

  • Wait 24 hours before using the soil.

  • Warm soil is an excellent way to stimulate mycelium growth! But if the soil is too hot, it’ll kill your mycelium! So please be patient =)

The coco coir and vermiculite provide natural hydration storage for your mycelium while the water provides much-needed moisture to keep your mushrooms growing strong. The pasteurization process kills much of the harmful bacteria but leaves some that are beneficial for forming mushrooms!


In conclusion, making your own soil using coco coir, vermiculite, and water is a cost-effective and customizable way to ensure that your plants have the perfect growing environment. Not only is this soil mix easy to make, but the ingredients used to provide a range of benefits for mushrooms including good drainage, proper aeration, and the ability to retain water. By following the steps outlined in this post, you'll be well on your way to creating a healthy and thriving indoor garden.


If you're interested in purchasing high-quality coco coir, vermiculite, or any other gardening supplies, be sure to visit our online store. Use promo code "MushroomSoil" at checkout to receive a special discount on your purchase. Happy mushroom gardening!

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