Five-pound bags of fully colonized grain spawn, grown on a fine millet blend from our first-generation genetics and shipped the same or next business day. Break the bag up and mix it into Master's Mix, supplemented sawdust, straw or a bulk bed. There's no inoculating and no waiting on colonization. One bag spawns 12–13 bags of 5 lb Master's Mix.


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Black Pearl King Oyster Colonized Grain Spawn, 5 LB Millet Bag (Pleurotus hybrid)
Retail: $29.99
Price: $24.99
Availability: In Stock
Item #: BPKGS -

    Black Pearl King is a hybrid of Oyster and King Oyster. It pairs the speed and vigor of an oyster with the thick, meaty stem of a king, under dark gray-black caps that stand out wherever you sell them. HybridSpecies ~5 lbColonized grain 60–70°FFruiting temp Beginner+Skill level 12–13Master's Mix bags Why grow Black Pearl King from our spawn Best of both Oyster-like colonization speed with king-oyster substance and flavor. Forgiving A robust hybrid that tolerates small mistakes. Distinctive...

    Blue Oyster Colonized Grain Spawn, 5 LB Millet Bag (Pleurotus ostreatus)
    Retail: $29.99
    Price: $24.99
    Availability: In Stock
    Item #: BOGS -

      Blue Oyster is one of the fastest, most aggressive colonizers you can grow, which is why commercial farms and first-time growers both rely on it. Caps open blue-gray and lighten to a silvery tan as they mature. P. ostreatusSpecies ~5 lbColonized grain 55–65°FFruiting temp BeginnerSkill level 12–13Master's Mix bags Why grow Blue Oyster from our spawn Outruns problems Aggressive mycelium claims the substrate quickly, leaving little room for contaminants. Heavy yields A forgiving, productive...

      Chestnut Colonized Grain Spawn, 5 LB Millet Bag (Pholiota adiposa)
      Retail: $34.99
      Price: $28.99
      Availability: In Stock
      Item #: CMGS -

        Chestnut grows clusters of golden-brown caps with a crunchy texture and a sweet, nutty flavor. Unlike delicate oysters, it keeps well after harvest, which makes it a practical choice for market and restaurant sales. P. adiposaSpecies ~5 lbColonized grain 50–65°FFruiting temp IntermediateSkill level 12–13Master's Mix bags Why grow Chestnut from our spawn Stores well Holds up after harvest far better than delicate oysters. Cool-room grower Fruits at 50–65°F. Great texture Crunchy, with a sweet,...

        Golden Oyster Colonized Grain Spawn, 5 LB Millet Bag (Pleurotus citrinopileatus)
        Price: $34.99
        Availability: In Stock
        Item #: GOGS -

          Golden Oyster fruits in bright yellow clusters with a nutty, cashew-like aroma. It colonizes quickly, produces heavily and likes warmth, so it's a natural summer crop with color that stands out at the market. P. citrinopileatusSpecies ~5 lbColonized grain 65–80°FFruiting temp BeginnerSkill level 12–13Master's Mix bags Why grow Golden Oyster from our spawn Warm-season grower Fruits at 65–80°F, when cooler species slow down. Fast and prolific Quick colonization and generous clusters....

          King Blue Oyster Colonized Grain Spawn, 5 LB Millet Bag (Pleurotus hybrid)
          Price: $24.99
          Availability: In Stock
          Item #: KBOGS -

            King Blue is the cold-loving cousin of the classic Blue Oyster. It forms firm clusters of deep slate-blue caps with thicker, meatier flesh and a longer shelf life, and it keeps fruiting in cool, unheated spaces through fall and winter. P. columbinusSpecies ~5 lbColonized grain 45–65°FFruiting temp BeginnerSkill level 12–13Master's Mix bags Why grow King Blue from our spawn Cold-weather fruiter Fruits from 45 to 65°F, cooler than standard Blue Oyster. Meatier texture Thicker flesh and firmer...

            King Oyster Colonized Grain Spawn, 5 LB Millet Bag (Pleurotus eryngii)
            Retail: $29.99
            Price: $24.99
            Availability: In Stock
            Item #: KOGS -

              King Oyster (Pleurotus eryngii) is grown for its thick, meaty stems. Their firm, scallop-like texture holds up to searing, roasting and grilling, and the mild umami flavor makes them a restaurant favorite. P. eryngiiSpecies ~5 lbColonized grain 60–70°FFruiting temp IntermediateSkill level 12–13Master's Mix bags Why grow King Oyster from our spawn Restaurant quality Substantial fruits with a firm bite. Sawdust grower Best on Master's Mix or supplemented hardwood sawdust. Worth the...

              Lions Mane Colonized Grain Spawn, 5 LB Millet Bag (Hericium erinaceus)
              Retail: $29.99
              Price: $27.99
              Availability: In Stock
              Item #: LMGS -

                Lion's Mane is prized in the kitchen for its tender texture and mild, seafood-like flavor, and it's just as popular as a functional mushroom. This bag arrives fully colonized with bright white, cottony mycelium, ready to spawn into Master's Mix or supplemented hardwood. H. erinaceusSpecies ~5 lbColonized grain 60–70°FFruiting temp BeginnerSkill level 12–13Master's Mix bags Why grow Lion's Mane from our spawn Beginner-friendly Straightforward to grow from colonized spawn, fruiting at 60–70°F....

                Maitake Colonized Grain Spawn, 5 LB Millet Bag (Grifola frondosa)
                Retail: $34.99
                Price: $19.99
                Availability: In Stock
                Item #: MTGS -

                  Maitake, also called Hen of the Woods, forms large rosettes of feathery fronds with a rich, earthy flavor, and it has a strong reputation as a functional mushroom. It's slower and more demanding than most, so it's best for growers with a few harvests behind them. G. frondosaSpecies ~5 lbColonized grain 55–65°FFruiting temp AdvancedSkill level 12–13Master's Mix bags Why grow Maitake from our spawn Showpiece harvest Big, layered rosettes that stand out in any kitchen. Gourmet and...

                  Pearl White Oyster Colonized Grain Spawn, 5 LB Millet Bag (Pleurotus ostreatus)
                  Retail: $29.99
                  Price: $24.99
                  Availability: In Stock
                  Item #: PWGS -

                    Pearl White is the classic gourmet oyster: fast, forgiving and productive, with a mild flavor that works in almost any dish. Its wide temperature range makes it a dependable year-round crop at any scale. P. ostreatusSpecies ~5 lbColonized grain 55–75°FFruiting temp BeginnerSkill level 12–13Master's Mix bags Why grow Pearl White from our spawn Widest range Fruits anywhere from 55 to 75°F, the broadest window of our oysters. Year-round staple Reliable enough to anchor a home grow or a small...

                    Pink Oyster Colonized Grain Spawn, 5 LB Millet Bag (Pleurotus djamor)
                    Retail: $34.99
                    Price: $26.99
                    Availability: In Stock
                    Item #: POCG -

                      Pink Oyster is the fastest colonizer of all the oysters. It loves warm weather and fruits heavily in ruffled, bright pink clusters that turn savory, almost bacon-like, when cooked until crisp. P. djamorSpecies ~5 lbColonized grain 65–85°FFruiting temp BeginnerSkill level 12–13Master's Mix bags Why grow Pink Oyster from our spawn Fastest oyster Very quick, aggressive colonization. Built for heat Fruits at 65–85°F, when most species struggle. Big yields Heavy flushes of ruffled pink clusters. A...

                      Pioppino Colonized Grain Spawn, 5 LB Millet Bag (Cyclocybe aegerita)
                      Retail: $29.99
                      Price: $24.99
                      Availability: In Stock
                      Item #: PPCG -

                        Pioppino grows clusters of bronze-brown caps on crisp white stems, with a rich, nutty, slightly peppery flavor. It holds its texture in the pan and keeps better than most gourmet varieties, which has made it a long-time chef favorite. A. aegeritaSpecies ~5 lbColonized grain 55–65°FFruiting temp IntermediateSkill level 12–13Master's Mix bags Why grow Pioppino from our spawn Chef favorite Firm texture and a nutty, peppery flavor. Keeps well Stores better after harvest than most gourmet...

                        Red Reishi Colonized Grain Spawn, 5 LB Millet Bag (Ganoderma lucidum)
                        Price: $26.99
                        Availability: In Stock
                        Item #: RRCG -

                          Red Reishi (Ganoderma lucidum) is the classic lacquered, deep-red polypore and one of the most recognized functional mushrooms. It's tough and contamination-resistant on grain, then rewards a long, warm fruiting cycle with either branching antlers or flat conks. G. lucidumSpecies ~5 lbColonized grain 70–85°FFruiting temp IntermediateSkill level 12–13Master's Mix bags Why grow Red Reishi from our spawn Hard to contaminate Dense, vigorous mycelium that's easy to colonize. You choose the...

                          Shiitake Colonized Grain Spawn, 5 LB Millet Bag (Lentinula edodes)
                          Retail: $31.99
                          Price: $24.99
                          Availability: In Stock
                          Item #: SHCG -

                            Shiitake brings deep, savory umami and a meaty texture, which is why it's a kitchen staple around the world. It takes longer than oysters, including a browning phase before fruiting, but rewards patience with restaurant-quality harvests. L. edodesSpecies ~5 lbColonized grain 55–70°FFruiting temp IntermediateSkill level 12–13Master's Mix bags Why grow Shiitake from our spawn Restaurant quality Rich umami and a firm, meaty bite. Built for blocks Best on supplemented hardwood sawdust or Master's...

                            Turkey Tail Colonized Grain Spawn, 5 LB Millet Bag (Trametes versicolor)
                            Retail: $29.99
                            Price: $24.99
                            Availability: In Stock
                            Item #: TTCG -

                              Turkey Tail is a multicolored, fan-shaped polypore and one of the most widely studied functional mushrooms. It colonizes grain and bulk substrate fast, and as a natural wood decomposer it does well on blocks and logs. T. versicolorSpecies ~5 lbColonized grain 55–75°FFruiting temp BeginnerSkill level 12–13Master's Mix bags Why grow Turkey Tail from our spawn Fast colonizer Aggressive mycelium that's easy to get going. Wood lover Runs on Master's Mix, supplemented hardwood sawdust or hardwood...

                              Pick a species

                              SpeciesFruiting tempSkill level
                              Blue Oyster (Pleurotus ostreatus)55–65°FBeginner
                              Pearl White Oyster (Pleurotus ostreatus)55–75°FBeginner
                              King Blue Oyster (Pleurotus columbinus)45–65°FBeginner
                              Golden Oyster (Pleurotus citrinopileatus)65–80°FBeginner
                              Pink Oyster (Pleurotus djamor)65–85°FBeginner
                              Lion's Mane (Hericium erinaceus)60–70°FBeginner
                              Turkey Tail (Trametes versicolor)55–75°FBeginner
                              King Oyster (Pleurotus eryngii)60–70°FIntermediate
                              Black Pearl King Oyster (P. ostreatus × P. eryngii)60–70°FBeginner to intermediate
                              Shiitake (Lentinula edodes)55–70°FIntermediate
                              Chestnut (Pholiota adiposa)50–65°FIntermediate
                              Pioppino (Agrocybe aegerita)55–65°FIntermediate
                              Red Reishi (Ganoderma lucidum)70–85°FIntermediate
                              Maitake (Grifola frondosa)55–65°FAdvanced

                              Spawn it intoSterilized Master's Mix (5 lb) for gourmet blocks, or Myco Labs CVG bulk substrate for monotubs. Prefer to start from a culture? See colonized agar plates and liquid culture syringes.

                              Common questions

                              How much substrate does one bag cover?

                              At about 1 part spawn to 3 parts substrate, one 5 lb bag spawns 12–13 bags of 5 lb Master's Mix, roughly 2 cups per bag.

                              When does colonized spawn ship?

                              Bags are made fresh on a rolling schedule and usually ship the same or next business day, with a free cold pack from May through September or for hot destinations.

                              How long does colonized spawn keep?

                              Use it within about 90 days for best results. Refrigerated at 35–40°F, it can last around 120 days.

                              Do I need a flow hood to use it?

                              Not for a basic spawn into Master's Mix in a clean, still room. For grain-to-grain expansion or other open work, use a flow hood or clean room.

                              What if a bag arrives contaminated?

                              Every bag is inspected before it ships. Contact us within 5 days of delivery with a photo and we'll send a free replacement.