Black King Oyster | Pleurotus ostreatus- hybrid | Mushroom Grow Kit- Spray and Grow

About This Kit

Zero Maintenance Kit
Everything you need is included — just add water and follow the simple instructions.
Our substrate is a special Master’s Mix: a blend of sawdust and lupin hulls, inoculated with 300g of millet grain spawn to give your mushrooms the best possible start.

This hybrid variety, sometimes called the Black Pearl King Oyster, combines the meaty texture of King Oyster with the resilience and deep-coloured caps of specialty strains.

Humidity: Maintain 85–93% RH during fruiting. Mist 2–3 times daily.
Light: Needs indirect light for proper cap development. Avoid direct sunlight.
Air: Gentle airflow is essential.

Black King Oyster Mushroom Grow Kit – Hearty & Gourmet

The Black King Oyster is a hybrid strain of Pleurotus ostreatus, famous for its thick stems, chewy texture, and umami-rich flavor. With darker caps and a robust form, these mushrooms are ideal for stir-fries, grilling, or even as a meat substitute.

Unlike common Oyster mushrooms, Black King Oysters prefer cooler fruiting conditions (15°C–21°C), making them an excellent choice for indoor setups in mild climates. With the right care, each kit can yield multiple flushes totalling up to 1.3kg of fresh mushrooms.

They are also valued for potential health benefits, including cholesterol-lowering properties and antioxidants that support immune health.

Common Mistakes to Avoid

Temperature: Black King Oysters won’t fruit well in warm conditions. Ensure 15–21°C for best results.
Humidity: Low humidity causes cracked caps and small fruit bodies. Mist frequently.
Air Exchange: Poor airflow leads to long stems and tiny caps. Keep gentle ventilation.
Light: Needs indirect light. Too dark = poor formation, too bright = drying.
💡 Tip: If mushrooms grow with long stems and tiny caps, it’s a sign of excess CO₂. Increase airflow.

What if pins form inside the bag?
Don’t worry. Ignore the internal pins. Gently fold the top of the bag to push out excess air, cut a small X in the side of the bag where you want the mushrooms to grow, and begin misting that spot daily. The internal pins will be naturally aborted as they don’t have space to grow.

Want to Learn More?
This kit introduces you to Stage 3: Fruiting — the final step in mushroom growing. To explore all three stages (from spores to harvest), check out our Educational Mushroom Growing Kit.

Checkout all our Spray and grow kits.

Checkout out our fine Misting Spray Bottle to produce tiny droplets and keep humidity high. The size of droplets formed can easily be evaporated , this constant evaporation signals mycelium to pin.

Could not fruit the bag, or was it contaminated? Send us a photo or call us, and we will help you resolve the issue.