How long do mushrooms take to grow?
From spawn to your first harvest, most mushrooms take about 3 to 6 weeks — but the exact time depends on the species and whether you start from scratch or from a kit. Here is the full timeline.
How long do mushrooms take to grow? The honest answer is that most of the wait is invisible: the mycelium spends weeks quietly colonizing the substrate before a single mushroom appears, and then fruiting itself happens fast. Understanding the two phases — colonization and fruiting — is the key to knowing what to expect and where you can speed things up.
See the fastest way to start →
The mushroom growing timeline
1. Colonization (about 2–4 weeks). After you inoculate the substrate with spawn, the mycelium spreads through it. Nothing looks like a mushroom yet — the block just turns white. This is the longest phase.
2. Fruiting conditions (a few days). Once the block is fully colonized, you introduce fresh air, light and humidity. Tiny pins appear in about 5 to 10 days.
3. Harvest (3–7 more days). Those pins balloon into full mushrooms fast, roughly doubling in size each day near the end.
4. More flushes (every 1–2 weeks). After the first harvest, rest and rehydrate the block for a second and third flush.
This whole cycle is part of fungiculture, and once you have seen it once, the timing becomes second nature.
How long by species
| Mushroom | Spawn → harvest | Speed |
|---|---|---|
| Oyster | 3–5 weeks | Fastest |
| Lion's mane | 4–6 weeks | Quick |
| Shiitake (sawdust) | 2–4 months | Slow |
Want the details for each? See our guides on growing oyster mushrooms, lion's mane, and shiitake.
The grow-kit shortcut
If waiting a month for colonization sounds like a lot, a pre-colonized grow kit skips it entirely — the block arrives fully colonized, so you just open it, mist it, and harvest in 1 to 2 weeks. It is the fastest, most beginner-proof way to see a real harvest, and the best way to learn the fruiting stage before you scale up to your own substrate.
Start growing this week
A ready-to-fruit kit gets you from box to harvest in days, not weeks.
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How long do mushrooms take to grow — FAQ
How long do mushrooms take to grow?
About 3 to 6 weeks from spawn to first harvest — roughly 2 to 4 weeks to colonize, then 1 to 2 weeks of fruiting. A grow kit fruits in 1 to 2 weeks.
How long do oyster mushrooms take?
The fastest common type — about 3 to 5 weeks from spawn, or 1 to 2 weeks from a kit.
How long do shiitake and lion's mane take?
Lion's mane about 4 to 6 weeks; shiitake on sawdust is the slow one at 2 to 4 months.
How can I grow mushrooms faster?
Start from a kit or fresh spawn, keep temperature and humidity ideal, and pick a fast species like oyster.