Mushroom Fruiting 101: Creating the Right Conditions for a Great Harvest

Video credit : PhillyGoldenTeacher (Web, Youtube)

Fruiting — The Stage Everyone Waits For

Colonisation feels like a lot of watching and waiting, right? The block just sits there turning white. But once it’s done, the fun part finally kicks in: fruiting. That’s when the mycelium actually starts making mushrooms. Real, edible ones you can cook with. The stage where all the patience pays off.

What Fruiting Really Is

In nature, mushrooms “decide” to fruit when the seasons shift—usually in spring or fall. Cooler air, more moisture, less CO₂. Indoors, we just trick them into thinking those changes are happening. That’s basically what fruiting conditions are: a set of signals telling the mycelium, “okay, time to make mushrooms now.”

The Things You Need to Get Right

• Airflow: Mushrooms breathe oxygen, not CO₂. Without fresh air, you’ll see stretched, skinny fruits (oysters especially get those fuzzy, leggy stems). Even a basic tent with a couple of holes for air exchange helps.

• Humidity: They dry out fast if the air isn’t damp enough. 85–95% humidity is the sweet spot. Oysters like it on the high end, lion’s mane a bit less but still moist, shiitake can get by starting closer to 85%. A cheap humidifier or just frequent misting can work.

• Temperature: Each type has a preferred range. Oysters: 15–24°C. Lion’s mane: 18–21°C. Shiitake: cooler, around 13–20°C. Off by too much? Growth slows or stalls.

• Light: Mushrooms don’t “eat” light, but they need it as a signal. A little window light or an LED on a timer (12 hours on/off) does the job.

• Moist surface: If the block dries out, fruiting stops. You want it damp to the touch, not soggy. A light misting is usually enough.

How to Kick It Into Fruiting Mode

After the block is colonized:

1. Move it to a spot with more airflow and some light.

2. Keep humidity high.

3. Match the right temperature for the species.

4. Then… wait. Usually within a few days you’ll see little pins popping out. That’s the signal it’s working.

Things That Go Wrong (And Why)

• No pins? Almost always humidity or airflow.

• Mold showing up? Usually over-misting or poor ventilation.

• Mushrooms stretched out and weird looking? Too much CO₂ hanging around.

Small-Space Fruiting (Yes, Even in a Flat)

You don’t need a greenhouse. In a city apartment—even somewhere like Prague—you can do it with a plastic tent, a humidifier, and a cheap grow light. Oysters, lion’s mane, shiitake—they all adapt fine indoors. Once the setup’s dialed in, the mushrooms more or less do the rest.

Wrapping Up

Fruiting is the fun part. It’s where weeks of waiting suddenly turn into real mushrooms you can harvest. Get the basics right—humidity, air, temp, light—and you’ll be rewarded with flushes of fresh mushrooms. And honestly? Seeing the first pins appear never really gets old.

If you are interested in learning more about our 4.0 Farm : https://bohemianfungi.com/en/farm-40

A big thank you to PhillyGoldenTeacher for their videos always done with a lot of details : Youtube