What Causes Mushrooms in Your Lawn?

Many mushrooms growing in the lawn in the front yard of a house

We have all been there, you wake up in the morning, walk out to the yard to appreciate your perfectly manicured lawn, and you are met with a bunch of unsightly looking mushrooms.

It’s good to know that this is not the end of the world for your lawn and actually can provide some valuable information about what is happening beneath the surface.

When the conditions are right, the lawn mushrooms you see popping up are actually the fruit of the organism that has grown out of the ground.

The underground root system known as the mycelium grows a small pinhead called a primordium in the humid environment beneath your lawn’s thatch. Once this has fully formed, it absorbs water from its surroundings, balloons up to its full size and releases its spores.

Although mushrooms sprout and then disappear quickly, the network of microscopic roots that are growing beneath the surface can continue to spread and thrive in your yard for years.

To fully explain how to manage the mushrooms growing in your yard, first, we need to understand what exactly is a mushroom.

What are mushrooms?

Childs hands holding a bunch of large mushrooms

Mushrooms are the fleshy fruiting body of some varieties of fungus. They are commonly found growing out of the ground on soil or from decaying wood or tree roots.

The mushrooms that typically come to mind when talking about the ones growing around your house are made up of a Stem, a cap and gills. Beneath the surface though, is a far-reaching network of roots called mycelium.

These mycelia spread beneath the ground, breaking down and feeding on the nutrients in your soil. While the mushrooms that we see come and go, the mycelium can live on for years undetected beneath the surface.

A fun fact about mycelium is that one located in Oregon’s Blue Mountains currently holds the record for the largest organism on earth spanning 10 square kilometres.

This specimen is estimated to weigh as much as 31,000 Tonne and is about 2400 years old, rightly earning itself the nickname “The Humongous Fungus”.

For the Mycelium to end up in your backyard, it was first carried into your yard as a spore, finding a nice nutrient-rich place to germinate.

How do mushrooms grow out of nowhere?

The life cycle of a mushroom from spore release to spore germination, to mycelium growth and finally to fruiting.

Mushroom spores that are released from the mushroom can be carried by the wind into your yard. Once it has found a suitable place it will begin to germinate and grow into the mycelium beneath the surface.

When the mycelium senses the conditions are just right, it condenses together to form Primordia, these are the small pinheads we mentioned earlier.

The Mycelium will sprout many of these primordia, it then selects the few it thinks has the best chance of developing into a healthy mushroom and puts all its energy towards their growth.

Out of sight beneath your lawn’s thatch, the primordia will steadily grow. Until in the final stages, they absorb the water from the surrounding environment and rapidly balloon up to their fully grown size.

It’s this process that makes them seem like they magically appear.

While it might seem like these mushrooms grow extremely fast and just appear out of nowhere, this process happens over several days.

 

What conditions do mushrooms need to grow?

Mushrooms growing in wet lawn

As there are countless varieties of mushrooms, the conditions needed to grow can vary quite a bit, this explains why different types of mushrooms seem to pop up at different times.

The majority of the Mushroom species you’re going to find in your yard thrive in moist soil when the external environment has humidity levels above 85% and temperatures between 15 and 25 degrees celsius.

What all this means is that you will most often find mushrooms sprouting in your yard after periods of rain, particularly during the more temperate times of the year.

Unlike plants, mushrooms do not require sunlight to grow, instead, they get all of their nutrients through the soil they are growing in. Many varieties actually prefer a nice shaded environment.

Are mushrooms in your yard a good sign?

Fungi like mushrooms have had a mutually beneficial relationship with plants for millions of years. Throughout time they have evolved to help each other out.

The mycelium help to break down the organic matter in the soil, freeing up the nutrients for the grass to feed on. They often attach themselves to the lawn’s root system helping the roots reach farther into the soil.

When the mycelium and plants roots fuse together like this they are called mycorrhizae. While mycelium is not a fertiliser, it can help to improve your lawn‘s growth rate and make it more resilient to drought and disease.

All of this means that most species of mushrooms growing through your lawn are a sign of good healthy soil. There are exceptions though, mushrooms like fairy rings that grow in a circle can be detrimental to the health of your lawn and should be dealt with immediately.

Mushrooms growing in a circle fairy ring on lawn.

FAQ

What causes mushrooms to grow out of nowhere?

Mushroom spores can be carried by the wind into your yard. These spores grow into a root system called mycelium beneath the surface. When the conditions are right the mycelium will grow a pinhead that absorbs water from its surroundings ballooning up to its full size rapidly, making the mushroom seem like it appeared out of nowhere.

Can you eat yard mushrooms?

While some mushrooms that grow in your yard are edible, many varieties are toxic or harmful to both humans and animals. As a general rule, you should avoid eating them and try to keep your pets away from them also, unless you are absolutely certain of the variety of mushrooms that you have growing in your yard.

What happens after a mushroom dies?

After releasing their spores mushrooms will shrivel up and decompose, while the rest of the organism growing beneath the surface, which is known as the mycelium, can live on for many years. The mycelium will continue to grow and produce more mushrooms until it has exhausted its food source or has been outgrown by a competing organism.

 

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