Organic Specialty Strain Grain Spawn
King Blue Oyster (Pleurotus ostreatus)
$29.99
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Bring uncommon mushroom varieties into your growing rotation with Organic Specialty Strain Grain Spawn. Created from North Spore’s extensive culture bank, these limited-edition releases make select strains available beyond the standard catalog.
Each bag contains fully colonized grain spawn prepared for expansion into a suitable bulk substrate. Grain spawn offers a flexible starting point for indoor cultivation, whether you are experimenting with a new species, refining a small grow, or building experience with advanced techniques.
Specialty releases may include varieties such as blue oyster, other oyster strains, hen of the woods (maitake), shiitake, and additional seasonal or limited-availability cultures. Exact strain selection varies, so each release offers an opportunity to work with something different.
All North Spore grain spawn is USDA Certified Organic and produced with careful attention to culture quality and contamination prevention. The result is a dependable foundation for growers who value clean, consistent materials.
For best performance, inspect the bag on arrival and follow the included or species-specific cultivation guidance. Store as directed and use clean technique when transferring spawn to substrate. Colonization speed and fruiting performance vary by species and growing conditions.
Availability is limited and changes as new cultures are selected from the culture bank. Recommended for indoor growers comfortable matching specialty strains with appropriate substrates and environmental parameters.
King Blue Oyster
Pleurotus ostreatus. High-yielding, thick-stemmed "King Blue" from Mossy Creek. King Blue oyster mushrooms are a cross between the blue and king oysters. They bring the beautiful color of the blue oyster, and the large, thick-stem of the king mushroom.
Popham Elm Oyster
Pleurotus ostreatus. Produces highly branched clusters of off-white/tan mushrooms that yield well in both cold and warm temperatures.
Belgium Hen of the Woods
Grifola frondosa. An alternative maitake strain from Belgium and an impressive contender for ease of cultivation for a notoriously difficult species. Fruiting bodies will develop fronds with proper oxygen levels and light.
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Reviews
J
King blue oyster are fun and easy to grow. I put my homemade block in wood chips on my deck for a second flush.
Congrats on your success! Thank you for sharing your harvest.
D
These elms do great is pretty much all reasonable weather. Huge flushes. Maybe the most aggressive strain I've used. Fruiting in the bag within 2 weeks or so from inoculation.
D
This is an aggressive strain. Likes cold temps. North spore spawn always reliable.
A
I had a blast with these! Beautifully healthy upon arrival and i had these shipped all the way to me in Portland, OR.
I grew these in straw and mulch in my old fire pit and inside of a mesh mannequin outdoors. They had a habit of fruiting when I least expected it.
What a unique grow, Angela! Thanks so much for sharing!
T
Fast shipping, arrived well packaged and smelling great/looking healthy. I made only a few fruiting bags, however, it seems to love both the master's mix and straw just fine. I will say that the master's mix looks to be a bit faster.
I'm excited to try the mushrooms when they grow -- I chose the Elm Oyster to see what that's all about. So far everything is going well! Love North Spore and their products, keep up the good work.
S
Letting it spread more in the bag before I attempt to fruit.
Thanks for sharing, Sara! If you need help with anything, please reach out.
J
I enjoyed many super tender and delicate Popham Elm mushrooms. I really like these! They also gave a second flush outside in wood chips.
Thanks for taking the time to leave a review, Janine!
G
I tried the Belgium hen of the woods. It was my first time growing maitake, and it worked! Most of the fruits were not fully developed but still delicious.
We're so glad the maitake worked out, Ginger! Our team is here if you need anything!
L
Really aggressive mycelium. Split it to 3 supplemented sawdust blocks and it fully colonized in 5 days and started fruiting in the bag 1 week later (huge clusters). Great strain selection on the part of northspore.
G
Absolutely love them.. would like to see more ... especially some comb tooth.. I would buy it on a regular basis
T
It was good but could be better. I received two bags of Pink oysters neither one fully developed. I think the cold weather during shipment may have n=been the culprit
D
Awesome spawn
D
Awesome spawn
D
Spawn is excellent
D
Spawn is excellent
M
Great variety. Easy to grow, with high yields.
L
It won't let me attach a pic to my earlier review, but here's a clump of the King Blue Oyster.
L
This was my first time growing in a monotub. In spite of being told that everything I did constructing it was wrong, I'm still getting a great harvest of delicious mushrooms.
J
Great, this company is 100! Legitimate and caring customer service
S
I bought the 'Comb Tooth' Hericium corraloides NSHC2.
It's a curious variety of lion's mane and impossible to find as spawn anywhere so I was delighted to see North Spore put it on offer. It survived the cold winter shipping conditions. It aggressively took over several more bags and is now in the process of fruiting. It seems just as aggressive as the other Lion's Mane they have that I ordered a while back.