Mushrooms are actually organs of a larger organism called a mycelium network, which includes all of that fiber you see when you pull one out of the ground. These organisms live for much longer than the existence of the mushroom cap, with some existing continually for thousands of years.
The caps on these organisms will live a few years at most before they start to petrify, but the underlying fibers continue to live on for a long time. When mushrooms pop up after a rainstorm in your lawn, they’re usually part of a much larger organism that spawns mushrooms when the conditions are right but goes dormant again whenever things dry up.
Most mushroom caps don’t live much after they release their spores, since they’re essentially just part of a fungi’s reproductive system. Their only purpose usually is to spread spores across a wider area.
Do Mushrooms Live Forever?
Gilled mushrooms don’t live forever, but if kept properly they’re viable and could fruit mycelium again if they’re put down on a nutritious substrate. In the wild, mushroom caps usually atrophy and harden after they release their spores.
If you bought a cooled mushroom stem from a grocery store and planted it in sterilized horse manure, then there’s a good chance that it could actually start to make a new mycelium network. That’s created the perception that mushrooms live forever even though they don’t.
The underlying fungus in most mushroom species can live for hundreds of years if the conditions are right for them to do so. In extreme instances, it might look like these examples could theoretically live forever.
It’s probably more accurate to say that their lifespans are finite but it’s hard to measure them because they’re just so long nobody wants to sit around and do so.
What is the Oldest Mushroom?
According to representatives of Malheur National Forest in Oregon, the oldest surviving mushroom is a specimen of Armillaria ostoyae growing in said forest. It’s believed to be over 8,600 years old and is still viable.
The oldest mushroom ever to have lived on record, according to representatives of the Smithsonian, is a 5cm tall droopy cap found in the fossil record at the Crato Formation in the Araripe Basin of northeastern Brazil. This dates to around the Early Cretaceous period.
Likely, there are actually older mushrooms that are still extant and viable, but they haven’t been discovered yet. Most of these consist primarily of massive underground mycelium networks, so it’s sometimes hard to see them.
One network in Crystal Falls, Michigan amassed so much fiber that it probably weighs over 800,000 pounds and has been in existence for around 2,500 years. This has helped many scientists remain hopeful that there are older examples still surviving in the wild.
Does Picking a Mushroom Kill It?
Picking a mushroom usually doesn’t kill the underlying fungus, and the mushroom cap itself should still be viable enough that it could sprout more mushrooms if planted properly. Eventually, the mushroom you picked may die off and be unable to sprout again.
Merely severing the mushroom from the rest of its fiber network doesn’t actually kill it, and it can normally make genetic copies of itself if the conditions stay right. If you allow it to dry out, however, this will cause it to die in time.
Likewise, the mycelium network shouldn’t actually die because a mushroom cap or stem has been removed from it. Delicate cultivated culinary mushrooms, like some types of hard-to-grow like chanterelles, may not be able to survive even the most gentle separation before they’re ready to be harvested.
How Do Mushrooms Die?
In theory, the mushroom fungus can die of old age, but most biologists seem to be unsure of how long the lifespans in question are. They might be measured in thousands of years or even longer, making it unlikely that anyone will be able to simply measure the lifespan of any given fungus.
Excessively dry conditions can kill a mushroom fungus, as can a lack of food. Mushrooms that are growing on a log might die off naturally after they run out of decaying log material to feed on.
Additional cultures in an area can kill a mushroom as well. This is one of the most common causes of death for cultivated culinary mushrooms.
When another type of unwanted fungus or bacteria starts to grow on the same substrate as the mushroom material, it can choke it out by taking away all of its moisture and food. This will allow it to grow at the expense of the mushroom in question.
Do Mushrooms Come Back Every Year?
Local rainfall levels and the amount of food that any particular mushroom specimen has will dictate whether or not it will come back every year. If there’s plenty of moisture and the ground contains a large amount of decaying material, then mushroom caps should continue to pop up regularly.
That being said, mushrooms aren’t the same things as perennial crops. They don’t grow based on any seasonal rhythm like true plants would.
Some mushrooms, like ink caps, just tend to pop up at regular intervals whenever there’s enough moisture and food for them to do so. They’ll then decay and drop off as soon as the conditions start to change, especially if they suddenly lose access to whatever dead material that they’ve been feeding on.
Are Dried Mushrooms Dead?
Dried mushrooms are dead and can’t come back to life. They might still have viable spores inside of them that can produce new growth, however.
If a dried mushroom gets crushed, then this considerably reduces the chances that it could grow any new mycelia. Mushrooms that are very carefully handled, however, could potentially be used to fruit new growth because they have enough spores inside of them that they would be able to produce spawn.
The amount of time that’s passed since the mushroom was first dried out plays a big role in deciding whether or not a particular specimen could become viable. While scientists have found spores that are years old and still grow well, you normally won’t get very good results by doing so.