How long does mycelium live?

When you pick a mushroom, you take only its "fruit" — the fruiting body it needs to spread spores. The organism itself — the mycelium — stays hidden in the soil or wood all along, as a fine web of threads. And it lives incomparably longer than a mushroom that came up for a day or two.

Let's look at how long mycelium lives and why it's called nearly immortal.

A mushroom is only the fruit

A mushroom's fruiting body lasts just a few days: it grows, spreads its spores and dies off. But the mycelium that produced it keeps living in the soil and gives new mushrooms the next season. That's why a good mushroom spot "works" year after year — it's the same mycelium.

How many years mycelium lives

The lifespan of mycelium varies a lot:

• A few years — in fungi tied to a short-lived substrate (for example, on a rotting stump).
• Decades — in mycorrhizal fungi tied to trees; the mycelium lives as long as its partner tree does.
• Centuries and millennia — in some soil fungi that spread outward.

The largest and oldest organism

One of the best-known examples is a honey fungus in the USA (Oregon), whose mycelium covers thousands of hectares and is estimated to be about several thousand years old. It's one of the largest and oldest living organisms on Earth — and it's a mycelium.

Why mycelium is nearly immortal

Mycelium grows at its edges, constantly taking over new substrate, while the old parts die off — but the organism as a whole lives on. As long as there's food and moisture, mycelium can spread practically without limit. On how mycelium grows and how mushrooms reproduce, we have separate articles.

Sources

• "Field Guide to the Mushrooms of Ukraine" (Kyiv, Naukova Dumka publishing house).
• Mycelium on Wikipedia.
• Armillaria on Wikipedia.