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How Big Do Mushrooms Get? This May Surprise You!

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It’s well known that some mushrooms can grow to huge sizes. But just how big do mushrooms get?

Mushrooms can grow up to 30 inches high depending on the variety. For instance, the giant puffball mushroom can grow to 35 inches wide and weigh up to 20 kg.  Mushrooms thrive in damp, dark conditions and the size and weight of the mushroom can get larger as far as the growing conditions and variety allow.

So why aren’t all mushrooms big as the giant puffball mushroom? In this article, I’ll share all you need to know about how big do mushrooms get by the variety and the conditions that can promote larger growth.

How Tall Can Mushrooms Get?

how big do mushrooms get

The size of mushrooms varies from one to another. Some mushrooms get 4 to 8 inches tall, while others may attain a height of 10 to 18 inches. However, the average length of mushrooms ranges from 2 to 12 inches.

The largest living organism in the world is actually a single mushroom colony! That’s right, honey mushrooms (Armillaria ostoyae) in Oregon cover 3.7 square miles and are estimated to weigh more than 3,000 tons. It’s estimated to be more than 8,500 years old. Pretty impressive, huh?

The Malheur National Forest is home to this humongous fungus whose size is estimated to be the largest of any single organism in the world, by mass.

What determines the size of mushrooms?

Mushrooms gain height as a result of their cell enlargements. The cells of mushrooms build up in the presence of some energy and more water consumption. When their cells get turgid due to water absorption, they tend to get taller. 

The size of mushrooms also depends on the substrate where it is grown. The substrate should be rich in essential nutrients to boost its size and growth. Composted manure (animal waste used as a fertilizer) is probably the best fertilizer to increase the size of mushrooms.

If you are interested in growing your own mushrooms, I have found this organic growing kit from amazon to be cost-effective and produce yummy mushrooms with minimal effort. It’s perfect for both beginners and enthusiasts alike.
You can find it by clicking here.

Mushroom Growing Kit 1

Conditions for Good Mushroom Growth

Most mushrooms grow best in temperatures between 55°F and 70°F, away from direct heat and drafts. 

The ideal humidity for mushrooms is greater than 90% humidity. 

Soil type: Loamy
Soil pH: Neutral
Sunlight: Full shade, partial shade
Soil moisture: Moist but well-drained
Distance between: Up to 10cm (4in) apart

See our detailed post on how to grow mushrooms (from incubation to harvesting) which goes in-depth with the conditions needed to get the best results when growing mushrooms.

Can Mushrooms Be as Big as a Tree?

In recent times, nobody has claimed to see or grow a giant mushroom competing for the size of a tree.

Typically, mushrooms grow to a standard height, and some found in the dark forests may attain a bigger size than the others.

Scientists found a tremendous organism buried beneath the earth in Saudi Arabia when they dug up the land, searching for fossils. They claimed that this large organism is a fungus, and they declared it a Prototaxite (a giant fungus). 

Therefore, some ecologists and researchers believe that mushrooms used to be giant in ancient times, before the existence of trees. 

However, more research is required as it’s an unproven claim that the humongous fungus found in Saudi Arabia was really a mushroom (all fungi are not mushrooms).

Are Giant Mushrooms Edible?

The size of mushrooms does not have any impact on their edibility. You can ignore their size while eating mushrooms because it has nothing to do with their edible nature. 

But you must take the appropriate measures before consuming the wild mushrooms to identify whether they are edible. 

Here are a few things that you need to take into your account before adding mushrooms to your diet. 

Edible MushroomsPoisonous Mushrooms
Mushrooms that grow on wood or grassy lawns are mostly edible.Mushrooms growing on stinky garbage heaps or in polluted areas might be poisonous.
They have a pretty delicious taste and pleasing aroma.Poisonous mushrooms usually feel a chilly taste when placed on the tongue.
Edible mushrooms do not have scales on their cap. They mostly have a globe-like plane cap.Mushrooms having a red-colored cap or stem and also with white gills are known to be toxic.
E.g., shaggy mane mushrooms, giant puffball mushrooms, and meadow mushrooms.E.g., death cap mushroom, deadly dapperling, and autumn skullcap.

Cautionary Note: 

Some edible mushrooms are replicas of poisonous mushrooms. Therefore, you should also consult an expert despite taking the above measures.

What Mushroom is a Big White Ball?

The big white ball mushroom is known as the Giant Puffball. Its scientific name is Calvatia gigantia. It has a tremendous white-colored shape like a ball, due to which locals call it a big white ball mushroom.

Giant Puffball (Calvatia gigantea):

Giant puffball mushrooms were first found in the lands of England. It is commonly cultivated and harvested commercially in many countries and is openly available to consumers in the markets.

It usually grows in grassy lands, meadows, and forests when the trees shed their leaves in autumn.


Giant puffball mushrooms typically grow to a height of 4 to 20 inches and are almost 35 inches in diameter. Depending upon some healthy circumstances, these big white balls may also extend to a massive size of 35 inches and weigh about 20 kg.


Calvatia Gigantea is blessed with a sparkling white globe-like appearance. Its glowing white color and considerable size make it attractive. 

Mature giant puffball mushrooms show a greenish-brown look from the inside when you cut them. In contrast, the immature mushrooms have a pure white color from the inside out.


Fresh and immature giant puffball mushrooms are edible. You can eat the timely harvested young mushrooms without any hesitation, but one must not take the risk to consume a rotten or an old giant puffball.

Giant puffball mushrooms start decomposing soon after the development of fruiting bodies. At that time, they become fatal to eat and may cause severe health issues. Its spores and caps are also used in medicines.


  • Giant puffball mushrooms are included in various dishes for cooking purposes and toppings on fast foods like pizza.
  • It can do wonders in reducing one’s weight because it is rich in protein and has low calories.
  • It is widely used for medicinal purposes to improve cardiovascular health and strengthen the immune system.
  • It can also be used to treat skin problems and to heal the bleeding nose.

Lookalike Mushroom: 

Scleroderma citrinum is another mushroom that looks the same as the giant puffball mushroom. It is known as the earthball mushroom.

At the time of fruit body production, it becomes purplish-black from the inside. Unlike the giant puffball mushroom, it is poisonous and might intoxicate when consumed.

What is The Largest Edible Mushroom?

Termitomyces titanicus is the giant edible mushroom globally. Its cap is quite considerable, which grows to an enormous 1 meter (3.28ft) in diameter and gets 22 inches in length. 

A French botanist Roger Heim explained this giant organism among the edible mushrooms in 1942. This type of mushroom is mainly found in Zambia and West Africa. It grows on the stem and roots of big trees.

Termitomyces titanicus owe their lives to termites because they thrive on combs formed by the termites. Termites feed on the trees and hence provide organic matter to mushrooms in the form of their excreta (waste matter such as feces).

Termitomyces titanicus develops the largest fruiting body that weighs almost 2 to 3 kg. It usually grows in winters, when the rain pours down. It has quite a delicious taste and gives a meaty taste when consumed.

Some Biggest Mushrooms Ever Found In The World:

There are various mushrooms of different sizes and weights growing in different corners of the world. I would highlight some of the giant mushrooms ever found.

Armillaria (Honey Mushroom):

Armillaria mushrooms are poisonous mushrooms that usually grow in woods in clusters. It invades about 3.4 square miles of area. It has a ring on its stem, and many dark brown scales cover that ring.

It is mildly poisonous and can cause serious health issues when eaten. Therefore, it must be checked and examined before cooking. It is mainly found in North America and Europe.

Armillaria ostoyae growing in the lands of Oregon (a state located in the pacific northwest of the US) has become a sensation due to its enormous size. 

The single armillaria organism has spread itself to an incredible 3,726563 m2 of an area in the Malheur National Forest of Oregon. This honey mushroom is said to be 8650 years old, and it is also termed as Oregon’s Giant.

Macrocybe Titan:

Macrocybe titan mushroom is found in the western hemisphere. Georgia is known to be its most usual habitat. It has the owner of having a larger gill (a set of tissues that look like sheets of paper, present below the cap of some mushrooms) than the other mushrooms.

These mushrooms have almost 100cm broad hats, and they grow in the form of clusters. Most of these mushrooms grow from the dead organic matter below the soil as filamentous hyphae. It was first known as Tricholoma Titans but later changed to Macrocybe Titans.

Macrocybe Titans is a Latin word that means “large head”. It is an edible mushroom, but you should confirm it from an expert because it is a wild mushroom, and you might be holding its look-alike. 

Pleurotus eryngii:

Pleurotus eryngii is an edible mushroom found in the Middle East, North Africa, and several parts of Asia. King trumpet mushroom is the longest and attains a maximum height of almost 2 feet. It has a brownish or pure white cap, and it spreads out a pleasant aroma before ripening.

“King Trumpet” and ” King Oyster” are other renowned names for this mushroom. It is the largest mushroom among its oyster family. It is the most reputed mushroom due to its savory taste and meaty texture. Unlike other oyster mushrooms, its stem is quite delicate and soft to eat.

Uses of Pleurotus eryngii:

  • This mushroom is rich in beneficial chemicals that strengthen the immune system.    
  • It also helps in reducing cholesterol levels. Hence, it decreases the risk of heart diseases.
  • It aids in creating immunity against Nematode (the most common parasite that mainly infects cats and dogs. It is also known as eelworm).
  • It is widely used for cooking purposes. Therefore, it is cultivated on a large scale to meet its lovers’ demands.

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