Why mushrooms grow in the same place every year

Updated 9 September 2026

Every forager has a patch they go back to year after year — and it is not superstition, it is biology. The mushroom you put in the basket is only the fruit. The organism itself lives underground, wrapped around the roots of one particular tree, and it stays there for decades. Here is why, which tree hints at which mushroom, why last year was heavy and this year is empty, and why a spot does not "wear out" because you keep coming back.

The mushroom is the apple. The mycelium is the tree

What we call a mushroom is a fruiting body: a temporary organ that appears for a few days, sheds spores and collapses. The real organism is the mycelium — a web of fine threads in the soil and the leaf litter. It is perennial. Picking a mushroom is like picking an apple: the tree stays, and fruits again next year.

How perennial is a matter of scale. The largest known living thing on the planet is a honey-fungus mycelium in Oregon's Blue Mountains: roughly nine square kilometres and an estimated two thousand years old. Your patch is humbler, but the principle is the same — as long as the mycelium has something to eat, it lives.

Why this exact place: mycorrhiza

Nearly all the mushrooms worth carrying home — porcini and other boletes, chanterelles, milk caps, saffron milk caps — are mycorrhizal. Their mycelium grows into the roots of a tree and trades with it: the tree hands over sugars it makes from light, the fungus hands back water and minerals it pulls from the soil better than any root can. Not a lodger; a partner.

Which gives you the key consequence: the mycelium lives as long as its tree. A spruce stands for a hundred years — and the porcini under it can keep coming for a hundred years. That is why old foragers talk about "their" trees, and chanterelle patches get handed down in families.

The tree tells you the mushroom

Since the mycelium is tied to roots, the species of tree is the most reliable clue to where to look. Some names spell it out:

• Birch bolete — birch, and nothing else. Orange birch bolete and aspen bolete — birch and aspen respectively, as the names say.
• Porcini / king bolete — spruce, pine, oak, beech, birch; each tree has its own porcini form.
• Chanterelles — conifers and oaks, in moss. Where do chanterelles grow?
• Slippery jacks (Suillus) — pines; the larch bolete only under larch.
• Saffron milk cap — pine and spruce.
• Honey fungus — the exception: it lives on stumps and dead wood, not on roots (more below).

The practical takeaway: in an unfamiliar wood, look up before you look down. A stand of old birches on the edge — look for birch boletes; spruce with moss and dappled light — chanterelles and porcini.

How "same place" — it is a matter of metres

Fruiting bodies appear where the mycelium is, and the mycelium is in the tree's root zone. For a mycorrhizal mushroom that is roughly the footprint of the crown: a radius of a few metres, rarely more than ten. So a saved spot on the map is not a square metre — it is "this tree and around it".

Grassland mushrooms that live on dead matter rather than roots — field mushrooms, funnel caps, parasols — form "fairy rings": the mycelium eats the middle bare and creeps outward at 10–30 centimetres a year. The ring you found will be a couple of metres wider in ten years, but still there.

Why last year was heavy and this year is empty

Mycelium in the ground is not a guarantee of mushrooms this season. A fruiting body appears when moisture and warmth line up: warm rain, then a few days at 12–20 °C, no frost. A dry August, and the mycelium simply skips a year — perfectly alive. An empty patch is not a reason to delete the spot. A clear-cut is (see below).

Hence the rule for going back: 5–14 days after a good rain, in season. Chanterelles and birch boletes come up fast; porcini take longer.

Picking does not exhaust a spot — tested for 29 years

The longest study on the question ran in Switzerland, in the La Chanéaz reserve: from 1977 to 2006 the same plots were either picked clean — sometimes by cutting, sometimes by pulling — or left entirely alone. Result: neither the harvesting method nor harvesting itself had any effect on future yields. The only thing that reduced mushroom numbers was trampling: compacted soil lets less air and water reach the mycelium.

The practice that follows is simple. You can go back to your spot every week. Just do not rake the litter (it holds the moisture the mycelium lives on), and do not have five people trample the same square.

What actually kills the mycelium

• Clear-cutting. The tree dies, its mycorrhiza dies with it. A spot on a clear-cut is gone for good; new mycelium arrives with the new forest in 20–30 years, but a different one.
• Draining or flooding. Ditching, a new forest road with a drain, a beaver dam.
• Soil compaction. Harvesters, skid trails, the worn "mushroom paths" near villages.
• Building and ploughing — obviously.

Fire varies: a ground fire is often survived, a crown fire kills along with the trees. Ordinary weather and even a hard winter do nothing to the mycelium — it sits below the frost line.

The exceptions: honey fungus and morels

Honey fungus is not mycorrhizal but a decomposer: it lives on dead wood. A stump or a fallen trunk feeds it for a few years, then the wood is used up and the mycelium dies or moves to the next stump. The spot "drifts" a dozen metres over a few seasons — save the patch of dead wood, not the point.

Morels are spring mushrooms and famously fickle. They like disturbed ground, burn sites and road edges, and no two years match. A morel spot is the least reliable of all — mark it, but do not count on it.

How to keep a map of your spots

• Point + tree + what you found. Not "chanterelles somewhere near the creek" but "spruce slope down to the creek, chanterelles under three old spruces". The tree is the thing that does not move.
• Date. Next year, go the same week, adjusted for the weather.
• Drop the pin while you are standing at the mushroom — not later at the trailhead, "roughly there". Five metres of error in a spruce wood is a different spruce wood.
• Do not mark everything. Five good spots you return to are worth more than fifty random ones.

And the thing we hear most often: "I know exactly where the patch is, but I couldn't find it this time." Knowing and finding are different jobs. Getting to one tree in a forest with no landmarks is the same problem as getting back to the car: it takes an arrow, not a memory.