Blue King Oyster mushrooms develop thick, meaty stems with broad blue-gray caps. They need good humidity, indirect light, and more fresh air than many beginners expect.

Your kit should already be fully colonized and ready to fruit.

Before You Begin

Place the kit in a location with:

• Indirect natural light
• Good fresh-air circulation
• Temperatures around 55°F to 68°F
• No direct sunlight
• No heaters, fans, or drying vents blowing directly on it

Cooler conditions usually help Blue King Oyster mushrooms keep their deeper blue-gray cap color.

Step 1: Open the Grow Area

Locate the marked grow window on the box.

Cut an X-shaped opening through the plastic grow bag behind the window. Each cut should be about 2 to 3 inches long.

Leave the substrate block inside the bag. Do not remove the entire plastic bag because it helps the block retain moisture.

Step 2: Mist the Opening

Mist the cut area with clean water 2 to 3 times per day.

The exposed surface should stay lightly moist, but not soaked or dripping.

Use a fine-mist spray bottle. Avoid spraying a heavy stream directly into the opening.

Step 3: Provide Light

Place the kit near a window or in a room with indirect light.

The mushrooms do not need direct sunlight, but they do need some light to grow in the correct direction and form normally.

Avoid dark cabinets or enclosed closets.

Step 4: Provide Fresh Air

Blue King Oyster mushrooms need regular fresh air.

Do not place the kit inside a sealed tote, closed cabinet, or airtight humidity tent.

If the mushrooms begin forming long stems with very small caps, they likely need more fresh air.

A normal open room with gentle air movement is usually better than a sealed space.

Step 5: Watch for Pins

Small mushroom pins may appear around the cut opening within approximately 5 to 14 days.

The first growth may look like:

• Small white bumps
• Short thick stems
• Tiny blue-gray caps
• Dense clusters near the opening

Continue misting around the opening. Once pins appear, avoid spraying them heavily at close range.

Step 6: Support Proper Growth

Blue King Oyster mushrooms naturally grow with thicker stems than standard oyster mushrooms.

For the best shape:

• Keep temperatures cool
• Maintain humidity
• Provide indirect light
• Give the kit plenty of fresh air
• Avoid overcrowding the opening with plastic

If necessary, gently fold the cut plastic away from the developing mushrooms so they have room to expand.

Step 7: Harvest

Harvest when:

• The caps have expanded
• The cap edges are still slightly curved downward
• The stems feel firm and dense
• The mushrooms have not become dry or soft

Do not wait until the caps curl sharply upward or begin dropping large amounts of spores.

Harvest the entire cluster at once.

Hold the cluster near the base and gently twist and pull it away from the block. You may also use a clean knife to cut it close to the substrate.

Growing a Second Flush

After harvesting:

1. Remove any loose mushroom tissue from the opening.
2. Allow the block to rest for several days.
3. Resume misting 2 to 3 times per day.
4. Keep the kit in the same cool, well-lit location.
5. Maintain fresh-air circulation.

A second flush may appear within approximately 1 to 3 weeks. Later flushes are usually smaller.

Troubleshooting

The mushrooms have very long stems and tiny caps

They need more fresh air. Move the kit to a more open area and avoid enclosed containers.

The mushrooms are pale instead of blue-gray

Cap color can vary with temperature, age, light, and genetics. Warmer conditions often produce lighter caps.

The mushrooms look dry or cracked

Increase misting slightly and move the kit away from fans, heaters, vents, and direct sunlight.

The pins formed but stopped growing

Check that the opening is not drying out. Also make sure the room is not too warm and the mushrooms are receiving enough fresh air.

Mushrooms are growing underneath the plastic

Light may be reaching another part of the block. Keep the rest of the bag closed and direct light toward the intended grow opening.

The block has yellow or amber liquid

Small amounts can be normal mushroom metabolites. A strong foul smell, slimy texture, or spreading green mold may indicate contamination.

Storage Before Starting

For best results, begin fruiting the kit soon after delivery.

For a short delay, keep the unopened kit in a cool location or refrigerator. Do not freeze it.

Cooking and Storage

Blue King Oyster mushrooms should be cooked before eating.

After harvesting:

• Store them in a paper bag or breathable container
• Keep them refrigerated
• Use them within several days
• Slice the thick stems into medallions or strips for cooking

Need Help?

Send us a clear photo of the kit along with:

• The date you started it
• Your room temperature
• How often you mist
• Where the kit is placed

We are happy to help troubleshoot your grow.