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Pasteurized Horse Manure Mushroom Substrates

From $20.00 From $15.00

Out of stock

(35 customer reviews)

$60/shipped on 4 Bag (56 Quart) orders. Select this option, NO COUPON REQUIRED!

For reference, 4 bags fills a 56 quart tub to 3-4″


Manure is bagged and cooking begins Saturday. Cooks are done throughout the weekend and into Monday.

If you order before Saturday morning at 9AM EST, your order will ship the next Monday.

β­πŸ’©πŸš¨ THIS PRODUCT IS TO BE USED IMMEDIATELY ON RECEIPT! If storage is needed you can put them into the fridge or freeze them for long term storage. β­πŸ’©πŸš¨

For custom blends, local pickup or bulk orders (250lb+), please contact us at LetsGrow@MycTyson.com

Our phase 2 composted manure mushroom substrate is a meticulously crafted, analyzed & lab tested blend of hay, straw, corn cobs, horse manure, chicken manure, coco shells, gypsum, cotton seed hulls, and perfectly hydrated to field capacity for optimal mycelial growth.

Guaranteed to arrive clean or your order will be replaced.


ONCE THE BAGS ARE OPENED, THE ABOVE GUARANTEE IS NULL AND VOID! We do everything we can to guarantee you’ll receive a clean product, what you do with it after opening is up to you!! We encourage you to compare our products against others, and look forward to your repeat patronage!

**We are happy to replace ANY order which incurs shipping related damage ASAP, at no added cost. Take photos & email us if there are any concerns!


SKU: 1287391244 Category:



Our pasteurized, composted, manure based mushroom growing substrate is made by our local, professional mushroom compost producing friends. Our friends have been producing commercial mushroom composts since 1958 and know a thing or two about dung loving mushroom substrates. Compost used for mushroom growing is specifically formulated for commercial levels of production, this is not the same as spent mushroom compost for gardens, that’s the stuff that’s already been run through!

This is an actual photo of the facility where your new substrate is made!

Your purchase will arrive in sealed, 4-5lb bags* – and is perfect for dung loving mushrooms (coprophiles) like Agaricus blazei, Agaricus bisporus or other cultivated species of dung loving mushrooms. πŸ’©πŸ„

*The volume does not change for the bags, depending on the composition of the blend the weights range from 4-5lb. This new blend is much more voluminous than our previous manure blend.

πŸ„ This manure substrate is perfectly suited for ANY dung loving mushrooms! πŸ’©

Grow directly in the bag, you can remove the top and case them (leaving 1-2″ of plastic for a perfect micro climate) or dump into a tub (4 bags gives a nice fill for a 56 quart tub) or many smaller containers (trays etc..) for spawning. Whichever route you take, this manure based mushroom substrate will without a doubt satisfy your home mushroom growing needs!

I like how it performs, but why is this substrate a bit slower?

The simplest answer to this is that there is much more available nutrition, and your mycelium is working hard to break down, digest and finally form fruiting bodies. On average you can expect an extra 5-7 days for colonization, but the wait is worth the 2-4X production, dense fruit bodies and happy harvests πŸ˜‰

What is the exact blend? Is this horse manure? πŸ΄πŸ’©”

Our previous blend was composted cow manure, it worked great but having experience in the commercial Agaricus industry, and seeing commercial levels of production using a highly specific blend of ingredients to optimize production and make the term ‘pounds per square foot’ something that home growers can start talking about. That said, here are the ingredients used, in no particular order, to blend together the best mushroom growing substrate possible:

    • Hay
    • Straw
    • Corn Cobs
    • Chicken Manure
    • Horse Manure
    • Coco Shells
    • Gypsum
    • Cotton Seed Hulls
    • Water

Your substrate has been meticulously prepared, analyzed and each batch is lab tested for quality.

What is the white stuff I see (mostly) on the corn cob, why is the corn cob even used?? 🌽”

Actinobacter remnants on corn cob in our substrate

Referred to as actinobacter, this white growth is used to break down the raw ingredients into easily digested inputs for mushroom growing. I like to call it actino because saying actinobacter is weird πŸ˜‚ This growth has been killed off but remnants may be in-tact and appear to be contamination but rest assured, there is no risk to your experiments! For more reading on actinobacter in composting, check this out.

The corn cob itself is used to buffer the high nitrogen content of the manure and add some carbohydrates to the overall nutrition of the collective substrate. No agricultural waste goes unused in mushroom growing!

With new things it’s nothing to be ashamed of if you need anything clarified or are concerned with trying something different. If you have any questions, don’t be shy to email us at LetsGrow@MycTyson.comΒ  and remember, while this is well suited for growing all dung loving mushrooms, we cannot offer advice which is Federally illegal. Please do not ask about using our product for anything illegal or you will be ignored. Don’t make us do that! πŸ˜‚

Shipping is in flat rate boxes only. If you order alongside other items these will ship separately.

This keeps costs lower (free boxes & supplies) as the weight (up to 30lbs can go in a large flat rate) is heavy & can be expensive to ship regardless of location, doubly so when you order more.

Your mycelium says ‘Thank You!’ in advance πŸ˜‚πŸ˜πŸ„


For more reading on compost, how it’s made, how it’s used and a detailed breakdown of the WHY behind mushroom compost, check out these articles from Penn State:

Six Steps To Mushroom Farming
Substrate Production For White Button Mushrooms
Basic Procedures For Agaricus Mushroom Growing

For visual learners, enjoy this video from Agriimagesuk over in Europe as they demonstrate how mushroom compost is made!

Additional information

Weight N/A
Dimensions N/A

1 Bag (Shoebox), 4 Bags (56 Quart Tub), 6 bags

35 reviews for Pasteurized Horse Manure Mushroom Substrates

  1. Brad r. (verified owner)

    Love it. Ordering more. I don’t have room to pasteurize a couple hundred pounds of manure I don’t have space to store. Fixed the last hurdle in my process.

  2. Ben G. (verified owner)

    Great substrate at a great price

  3. Gregory U. (verified owner)

    Decided to switch my substrate from a DIY solution to Myc’s Poop based substrate. The price of $60 for 20lbs shipped was worth giving it a whirl. I was impressed by this substrate, it had the perfect moisture content and super rich. The spawn loved it but took a bit longer to colonize as it had so much nutrients to feed off of before branching out. I am a big fan and can honestly say Myc’s Shyte is the Shyte!

    Pasteurized Horse Manure Mushroom Substrates
  4. . (verified owner)

    Good product would buy again

  5. Anthony B. (verified owner)

    O yeah I now know for sure this stuff works!

  6. Anthony B. (verified owner)

    Great stuff !

  7. Michael C. (verified owner)

    Arrived quickly with no contamination problems. I will be using your service again sir. πŸ‘

  8. Raymond P. (verified owner)

    The new manure mixture is out of this world, Definitely the strongest mycelium growth I’ve ever seen , very healthy and vigorous, I’m definitely looking forward to ordering more.

  9. Lesa H. (verified owner)

    I’ve ordered the manure substrate and have had GREAT results ! I haven’t had such great results with my DIY substrate mix, so I will ONLY use this substrate from here on out ! The agar plates are a great bargain, and I’ve had much success with those as well. You can tell MycTyson has a passion for mushroom growing, obvious to see from this wonderful and informative website to the careful packaging of his products. Count me in as hopelessly devoted and loyal customer ! A +++++++ !!

  10. Raymond P. (verified owner)

    By far the best formulated mixture in a pasteurized manure I’ve seen, mycelium growth is rapid & healthy. Moisture content seems to be spot.on, I couldn’t be more pleased, and I’m sure you will be too.

  11. Michael W. (verified owner)

    Very pleased with this product. Whatever the secret sauce is the mycellium loves it whole heartedly. I thought it was a little dry but the mycellium didnt seem to think so. Definitely will order again. Thanks MycTyson.

  12. Jake F. (verified owner)

    Was super excited to get this and learn about mycology! This guy goes above and beyond too! I will be a returning customer for sure, his blagar plates are awesome πŸ‘Œ [black agar carbon infused] and look professional. Can’t wait to get some lions mane going! Thanks myctyson! He also is thinking of the ecosystem and used cardboard and paper tape to mean that means alot. 5 stars!

  13. Scott D. (verified owner)

    This is a really excellent product that has, so far, performed at a much higher level than other substrate blends I’ve tried. The affordability is supreme and despite some shipping delays that were out of Mycs control, I would have no hesitation recommending this product to others. If you’re able, get at least 20lbs and store the extra in food saver bags in the freezer. Thaw the day before. Myc stayed that this mix might err on the drier side of field capacity, but I found that it was perfect on arrival. Now to get a bigger freezer!

  14. Brian M. (verified owner)

    Great looking quality product. Arrived as promised. On time. Not to mention. The customer service has been outstanding. Pricing is on point as well. Give it a try, you won’t be disappointed.

    • Myc T.

      I’m super stoked that you’re happy with the product and with the service you received! I really do try my best! If you ever need anything else email is the fastest way to reach me!

  15. . (verified owner)

    Fast Shipping and everything came very professionally packaged. MycTyson responded to my emails very quickly regarding longer storage of the substrate. I will be ordering again soon.

  16. . (verified owner)

    howdy myc! just gotta say you’ve got some good sh$t haha. I had a problem where one of my bags tore during shipping and I was able to get a replacement one no problem. you the man! will be ordering more soon! thank you for your great service.

  17. . (verified owner)

    This substrate is awesome! Had a family emergency come up, and didn’t use the substrate for over 2 weeks. My mycelium still devoured it! Thanks Myc Tyson.

  18. Oklahoma F. (verified owner)

    This substrate is awesome and can’t wait to place another order! Great customer service and response times!

  19. Jesse N. (verified owner)

    This substrate is fantastic – it smells amazing and your manure loving species will eat … the shit out of it. It’s fantastic stuff and I’m looking forward to trying others (like the sawdust) for ones like oysters!

  20. . (verified owner)

    Fantastic substrate, competitively priced, delivered on time and packaged with excellence. This is my new go to place for myco growing supplies. MycTyson delivers what he says he will!!!

  21. ophelia c. (verified owner)

    This this sh*t!! I love the smell, the product smells like heaven and is a paradise for my mycelium. AAAA+++ vendor. I adore Myctyson.

  22. . (verified owner)

    Love Love Love Myctyson, not only an all-around stellar dude. But honest and great product, I will not be buying any of my products again from anywhere else. My dung loving mushrooms love his subs and couldn’t get enough of it! Thank you again, love from Texas β€οΈπŸ„

  23. . (verified owner)

    S/o Myc Tyson For the beautiful Substrate can’t wait to use it ! Also by far the best time on shipping

  24. . (verified owner)

    My order came fast And they had very very good customer service with deathly order again!!!!

  25. . (verified owner)

    Excellent substrate. Comes quick and healthy. MycTyson is one of the most trusted people in the industry. I was recommended to him by a friend. Keep up the great work.

  26. . (verified owner)

    I’m ussualy not a high maintenance customer, but I feel like I can tell when people care about there work and the peeps who receive from itπŸ‘πŸ€˜

  27. . (verified owner)

    This is an excellent product β€” I used to grow with vermiculite, gypsum and coco choir. my grains took to this soil quickly and I’ve had growth that’s about twice as fast. It’s quality soil at a great price. I’ll probably be getting my soil here from now on tbh

  28. . (verified owner)

    Great customer service myc answered my questions I had almost immediately very personal experience will definitely order again

  29. . (verified owner)

    Best deal I’ve found online. Will continue to support!πŸ€™πŸ½

  30. . (verified owner)

    Ordered the new Manure Substrate. Very fresh and arrived quickly. The mycelium is colonizing very quickly in a matter of a couple of days. Will order again for sure. Great personal communication with the owner as well who addressed a concern I had.

  31. . (verified owner)

    Really happy with the product I received, came really fast and Myc seems like a cool dude. Currently watching the mycelium expand so I can attest to the viability of it. Awesome price, and really excited to see what my culture does with it. Thanks again (:

  32. . (verified owner)

    This guy is the real deal. Everything was as promised. Fast shipping, professional packing. I haven’t used it yet, but I do not doubt the quality of the product. The price was cheaper than all the big online vendors, and I guarantee none of them puts as much effort in as him. I usually don’t leave reviews, but I feel like he deserves it. I have spent thousands on substrate in the last few months before I stumbled upon Myctyson. I hope to give him all my business moving forward.

  33. Kevin B. (verified owner)

    Once again blown away with Mycs’ products. Perfect field capacity and mycelium is devouring it. Great price for an outstanding item. Cheers!

  34. . (verified owner)

    Always more than pleased with the order. Colonizing as we speak. Highly recommend

  35. Ryan T. (verified owner)

    Best substrate on the market! I’ve received manure and supplemented hardwood from Myc Tyson. I haven’t seen what the hardwood can do yet. But the manure is top notch. No major clumping that you have to break apart and risk contams with. And the time for the mycelium to devour it was quicker than any other substrate I’ve purchased before. I recommend coming here for all your mush needs! PS on the very slim chance that there is an error or delay in your order Myc Tyson makes up for it and has the best customer service!

    • .

      Thanks for the feedback Ryan! I’m happy that everything is performing to your expectations and even surpassing them! The hardwood is the same blend I use for other substrates that I make, you’re sure to love it! I now realize I should make an effort to remind growers that they will dry out if not used within a reasonable time after receipt! This is one reason I make them to order, you can store it in an air tight vessel to prevent this from happening!

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