All in One Mushroom Grow Bag for Multiple Flushes
Five pounds of pressure-sterilized substrate and grain in one bag. Our HB4 formula runs 50/50 millet and rye pre-spawn layered with coco coir, vermiculite, gypsum, and worm castings, and other nutrients, balanced to pH 6.0-6.5. No pressure cooker. No still air box. Just inject your spores or liquid culture through the self-healing port, let it colonize, and harvest.
We batch-test every bag before it ships. The Unicorn 10T-injection, .2 micron filter patch handles gas exchange throughout colonization and fruiting. Most growers see their first flush in 6 to 12 weeks. The bag supports 3 to 5 flushes total.
If your bag arrives contaminated, or contaminates before you inoculate it we replace it. That's our contamination guarantee.
"Pins popping after two weeks. This stuff is vigorous."Verified Grower
What's in the Box
Grain pre-spawn (50/50 millet and rye berries) + HB4 substrate (coco coir, vermiculite, gypsum, worm castings) in a Unicorn Type 14A filter patch bag with self-healing injection port.
Specs & Yield
Dimensions: 8" x 5" x 19" sealed. Total weight: 5 lbs. Expected dry yield: 1-2 oz per flush, 3-5 flushes per bag. pH balanced at 6.0-6.5.
Storage & Handling
Store at 60-70F in a clean, dark area. Do not refrigerate. Inoculate within 30 days of receipt for best results.
Shipping & Guarantee
Ships within 24 hours via USPS Priority. Free shipping on orders over $100. If your bag arrives contaminated or fails to colonize due to a manufacturing defect, we replace it at no cost.
What's Inside
Six ingredients. Zero guesswork.
The Payoff
What happens when all six ingredients work together.
Substrate Mix
The bulk growing medium where mycelium colonizes and fruits emerge. Our HB4 blend ships hydrated and ready to use.
Grain Pre-Spawn
The colonized grain that carries mycelium into the substrate. We blend two grains 50/50 for a reason.
The Payoff
What happens when all six ingredients work together.
Substrate Mix
The bulk growing medium where mycelium colonizes and fruits emerge. Our HB4 blend ships hydrated and ready to use.
Grain Pre-Spawn
The colonized grain that carries mycelium into the substrate. We blend two grains 50/50 for a reason.
Want the layers separately?
Same formula. More control.
Same competition-proven ingredients, broken out for growers who want to dial it in.
HB4 Worm Based High Performance Substrate
Our worm-casting substrate. Bring your own grain.
Multi Grain Matrix (4 lbs)
50/50 millet and rye. Ready to inoculate.
Common Questions
Before you buy.
What species can I grow with this bag?
Dung and coir loving species. Our worm casting blend provides the nutrient profile these species thrive on — built for supplemented, enriched substrates. Not intended for hardwood-loving gourmets like oyster, lion's mane, or shiitake.
How long from inoculation to first harvest?
6-12 weeks total. 3-6 weeks for grain colonization, then 2-3 weeks for fruiting conditions to produce pins. Temperature and strain both affect speed.
What if my bag gets contaminated?
If your bag arrives contaminated or fails to colonize due to a manufacturing defect, we replace it at no cost. Email us with your order number and a photo, and we'll get a new bag shipped within 48 hours. Read our full contamination guarantee.
Do I need any equipment to get started?
Just a spore syringe or liquid culture. No pressure cooker, no still air box, no laminar flow hood. Inject through the port and you're done.
How many flushes can I expect?
Most growers pull 3-5 flushes. Each flush produces dense, vigorous fruit bodies. Rehydrate the cake between flushes and keep humidity up for the best results.
What temperature does my grow space need to be?
72-78F during colonization, 60-75F during fruiting. A closet shelf or spare room works. No climate-controlled setup needed.
What Growers Say
Hear it from the grow room.
4.9 average across 66 reviews
★★★★★
"First time grower, was nervous about contamination. Bag colonized perfectly, got three solid flushes. Already ordered more."Marcus T. Verified Grower
★★★★★
"Tried DIY substrate for months. Contamination every time. Switched to MMP and haven't lost a bag."Sarah W. Verified Grower
★★★★★
"Monster mushrooms, flush after flush. Third bag and every one performs. This is the real deal."Devon K. Verified Grower
★★★★★
"Ordered on Monday, arrived Wednesday. Visible mycelium within a week. Full grain colonization by week 4, pins two weeks later. Best all-in-one I've used."James L. Verified Grower
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