8-Pack ‘Boomr Bag’ Manure-Based Sterile Mushroom Substrate














Media | Horse manure mix |
Moisture content | Hydrated to field capacity |
Carton size | 8 bags (40 lbs) |
Bag weight | 5 lbs each |
A $224 value!
Our best-selling Boomr Bag is a sterile bulk mushroom substrate formulated by mycologists to maximize your mushroom yield. It features a proprietary blend of composted horse manure, coco coir, and several quality substrate supplements (although we keep the exact blend a secret!) Over several years, it has been perfected for dung-loving mushroom species and is widely-trusted by mushroom growers.
Use Boomr Bag in monotubs, filter bags, and outdoor beds. Or, grow mushrooms from the bag or tray in a humidity-controlled grow room or Martha set up.
Spawn to bulk ratio:
We recommended mixing 1 colonized grain spawn bag with 2-3 Boomr Bags. (Higher inoculation rates may improve your success.)
Looking for single bags? Click here.
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- We recommend clean hands, latex or nitrile gloves, and sterile technique when using Boomr Bag to reduce the introduction of contaminants.
- Be sure to mix colonized grain spawn thoroughly into your substrate.
- It is best practice to wait a minimum of 1 week after arrival before using sterile substrates to ensure they were not compromised during transit. Rest assured that your purchase is 100% guaranteed. If your substrate was compromised, we will replace it.
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Boomr Bags should be stored at room temperature out of direct sunlight. No refrigeration is necessary. They can also be stored for several months before use.
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Our Boomr Bags are sterilized in a commercial-grade autoclave. Sterility is verified using biological indicators and temperature sensors.
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North Spore's products shall be used only for lawful purposes. North Spore does not condone Psilocybin (Psilocybe cubensis) or hallucinogenic (magic) mushroom growing in jurisdictions where it is currently illegal.
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Love it
Great stuff. Thank you
North Spore
Thanks, Conor! Our team is here if you need anything!

North Spore, Always Quality
Par for the course, my items arrived quickly and in perfect condition. This is my go to company for substrates!
North Spore
Thanks, Aaron! The team is here to help if you ever need anything.

Boomer bag
I like this substrate very much. More than others I have tried. And that staff at north store are great to deal with.
North Spore
Thanks so much, Lisa! We really appreciate the kind review.

The Nutrient Rich Life Blood of your Mushrooms
I have cultivated many varieties of mushrooms in this substrate and all have produced a bountiful harvest and solid 2nd flushes with the combination of fully colonized grain spawn bags and a regulated %RH, Temp and Timed Air Exchange. You will not fail.
North Spore
Thanks for the great review, Chad! We really appreciate your support.

Amazingly Quick!
I love those bags! That has to be the quickest colonizing substrate I have seen, and it is moist enough to where I don't have to do much work. Only complaint, it stinks. :)
North Spore
Thanks for sharing, Austin! We appreciate you taking the time to share your experience.

Highly recommend
Arrived in a timely manner and in perfect condition.
North Spore
Thanks so much, Mike! We really appreciate the kind review.

Wow the biggest fruits I've seen
I was super impressed when I saw the biggest mushrooms I have ever grown. Compared to a CVG substrate the difference is immense. I used CVG as a pseudo casing over the North spore substrate just because I had it.
North Spore
We love to read reviews like this! It makes what we do all the more worth it.

Awesome Substrate
Best substrate on the market by far! Never any issues with using your product! Kudos!
North Spore
Thanks for the great review, Randy! We appreciate your support!

Clean and sterilized
Beautiful

Great Starter
I bought this at the beginning of my Myco journey. It was very useful in helping me learn the basics before I was able to make my own substrate. Very high quality stuff.