how fast do mushrooms grow

June 28, 2026

Mushrooms can grow surprisingly fast once they get going, but the full answer depends on the species and the stage you’re counting from.

Quick Scoop

Many common cultivated mushrooms (like white button) are ready to harvest about 2–4 weeks after the substrate is inoculated.

Fast species such as oyster mushrooms can go from inoculation to harvest in roughly 2–3 weeks, with visible “pins” turning into full mushrooms in just 3–5 days.

Once the fruiting bodies appear, they can often double in size in about 24 hours under good conditions, which is why they seem to pop up “overnight.”

Slower species like shiitake can take several weeks to months (especially when grown on logs) before you see mature mushrooms.

In practical, gardener terms:
If you start a fast-growing variety like pink or other oyster mushrooms today, you might be picking your first flush in about 2–3 weeks, and after the pins show, you’ll notice dramatic, almost daily size jumps.

A common experience people report is going to bed seeing tiny pins and waking up to nearly full-sized caps the next day—that “overnight” magic is real, but it’s the visible finale of weeks of hidden mycelium growth.

Typical timelines by type (short list)

White button / brown / portobello: about 3–4 weeks from inoculation; once visible, harvest in roughly 4 days or so.

Oyster (especially pink): about 2–3 weeks total, with 3–5 days from pin to harvest; among the fastest growers.

Shiitake: from several weeks up to many months depending on whether they’re on sawdust blocks or outdoor logs.

So, “how fast do mushrooms grow?”
From the moment you see them: very fast—often doubling in a day. From the very start of the cultivation process: usually a few weeks for fast species and up to months for slower ones.

TL;DR:

From first mycelium to harvest: usually 2–4 weeks for fast types, several months for slow ones.

From pin to plate (visible baby mushroom to full size): often 3–5 days.

Growth rate once visible: can be roughly 4% per hour, doubling size in 24 hours in good conditions.

Information gathered from public forums or data available on the internet and portrayed here.