Buy 2 or more mushroom grow bags and receive $5 off your order!

‘Boomr Bag’ is a horse manure based sterile mushroom growing substrate. We spent three years developing and perfecting our bulk substrate blend. It is specially formulated for optimum mushroom growth. Read the instructions below for making an indoor edible mushroom tub!

  1. Boomr Bag is a proprietary horse manure blend perfected for growing legal dung loving species of fungi (i.e. Agaricus spp.)* The substrate is
    sterile and should have proper moisture content for fungal growth. Prepare your fruiting chamber or mono-tub by thoroughly cleaning it with isopropyl alcohol. Be sure to wear latex gloves and try your best to keep your work area exceptionally clean. There are plenty of Online guides to making a proper mono-tub and sterile technique. At the very least you will need a cleanable bin with holes stuffed with polyfill for air exchange. Make sure the bottom of the bin where the substrate is in contact is either painted black or opaque from some other light-blocking material!
  2. Open the Boomr Bag and dump the contents into your sterilized bin. Make sure you are wearing gloves. Check the hydration by squeezing a handful of the substrate. It should be at ‘field capacity’ for moisture, meaning you should be able to get a few drops of water out of squeezing a handful of the substrate. If you don’t get any drops, mix small amounts of sterilized water into the mix until it is at proper hydration. THIS IS IMPORTANTMushrooms exhale CO2 and inhale Oxygen. They will suffocate themselves if there isn’t adequate airflow! Make sure your bin has adequate airflow!
  3. It is recommended to use at least 1.5# of grain spawn per 5lb Boomr Bag. Higher inoculation rates may improve your success. Mix your grain spawn thoroughly into the substrate mix in your tub. Make sure your hands are clean and you are wearing latex gloves! Cover your bin with its lid but make sure you have filtered holes in it for air exchange. Incubation for most species will take at least 2-3 weeks. Some species will take longer. Keep an eye on the bin and look for healthy myceliation. Your bin should slowly be turning white, growing from each inoculation point of spawn.
  4. When your bin is fully colonized (don’t rush the process!) you will start to see mushroom pins or hyphae growing from the top of the substrate. At this point, you may choose to case your mushroom substrate with a thin layer of coco coir or other media. Keep your bin humid, keep the air flowing, and you should see significant mushroom growth within a couple of weeks!

*North Spore’s products shall be used only for lawful purposes!


You can also use Boomr Bags to grow mushrooms on outdoor beds!


5 reviews for ‘Boomr Bag’ Manure Based Sterile Substrate 5lb

  1. Rickey (verified owner)

    Verified reviewVerified review - view originalExternal link | usFlorida, United States

    My first attempt at growing my own stuff. Shipping was fast, website very helpful.

  2. Cody (verified owner)

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  3. AARON LEMBCKE (verified owner)

    Verified reviewVerified review - view originalExternal link | usWashington, United States

  4. Anonymous (verified owner)

    Verified reviewVerified review - view originalExternal link | usUnited States

  5. Anonymous (verified owner)

    Verified reviewVerified review - view originalExternal link | usUnited States

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