Why do I have mushrooms growing on my lawn?

I am often asked about mushrooms growing on lawns. So in this post I’ll try to explain a little about these mysterious organisms. Why do they seem to appear out of nowhere?

Mushrooms are the fruiting bodies of fungus that live on and in the soil. Toadstool is the old common name for poisonous mushrooms, but toadstools are still essentially mushrooms. These mysterious organisms play an essential role in the decomposition and recycling of organic matter into nutrients usable by plants.

Fungus are classified as neither plant nor animal. They have their own separate classification called the Eukaryotes, which also include yeasts and moulds.

For the majority of their lives, most fungus go about their business underground. They slowly decompose all of the dead and rotting organic matter that falls within their reach. Largely unnoticed, they slowly grow filament-like structures that are similar to roots, called Hyphae. Collectively, Hyphae is Mycelium. Some species of fungi exhibit these as curious white strands in the soil and on dead wood. This is how the fungus grows and searches out nutrients.

Many species of fungi live in symbiosis with a host plant, with each one mutually benefiting from the other. Identifying the plant on which a fungus is growing is one of the many methods that is used to correctly identify them, as many only exist alongside their host plants.

What is a mushroom?

A mushroom is the fruiting body of a fungus. These structures hold millions of fungal spores which, when released are carried by the wind to new locations for the next generation. They come in a fantastic array of shapes, colours and sizes. For a gallery of mushrooms that I have found on lawns in my area, check out my fantastic fungus gallery, where I post pictures of the most interesting ones I find.

A fungus will only produce a mushroom when the environmental conditions are ideal. This can be many years between fruiting seasons. I remember in the autumn of 2010, conditions were ideal for the large Bolete species of mushrooms. There was an invasion of a great many of these distinctive, large mushrooms on lawns all over the North West. This is why you may not see mushrooms on your lawn for many years. Then, all of a sudden, they’re everywhere!

Do mushrooms indicate a problem with my lawn?

The vast majority of mushrooms on a lawn do not indicate a problem, and are actually beneficial. They are just part of the natural ecology of the lawn.
However, if the mushrooms that emerge are arranged in a distinct circle or arc then this is a rare situation when the presence of a particular fungus will adversely affect the lawn and will need treatment. This will indicate the presence of a fairy ring, caused by the Mycelium fungus in the soil. These can be fascinating to look at, but can be devastating to the look of the lawn. I will try to cover fairy rings in more detail in a later blog post.

Many other fungus in lawns enjoy damp, carbon-rich soil and therefore are only an indication of a problem with the lawn, such as a low pH, poor drainage or an excess of organic matter such as leaves or wood chip on the lawn. I can test your pH levels and advise if treatment is necessary.

Of these common species found on British lawns, very few are poisonous. Even fewer are toxic enough to cause death. Even so, if you are considering handling or eating any mushrooms that you find growing on your lawn, then be sure to verify that it is an edible species from at least two reliable field guides or from someone who is an expert in the subject. If you are at all unsure of what you have found, just leave it alone and it will disappear in time.

Why do I have mushrooms growing on my lawn?

Mushrooms on your lawn can appear overnight and will usually only last a few days, so the majority should be left alone and will do no harm to the lawn. However, some of the larger species can be very unsightly and leave a mess after they have finished spreading their spores, so if you wish to remove them, just picking them and putting them on the compost heap will suffice (be sure to wear gloves or wash your hands after handling).

Also, some folk say picking them when you see them will help to reduce the number of mushrooms appearing on your lawn, but there are so many mushroom spores that it is probably inevitable that some will land on your lawn from another unpicked mushroom nearby!

The only way to be sure of removing mushrooms from your lawn is to replace the soil every year. This, of course, is ridiculous.

Finally, have a look at my gallery of lawn mushrooms where I will be putting my photos of interesting mushrooms I have found on lawns in my area. I have also answered some readers questions about lawn mushrooms.

If you have any questions or are concerned about unusual fungus your lawn, or any other lawn issues, please don’t hesitate to get in touch.

Kris Lord