Lawn Mushrooms

Have you noticed mushrooms growing in your lawn or new turf?

Are you concerned they could be a sign of a severe lawn issue?

Want to know how to get rid of lawn mushrooms?

I’ve had mushrooms in my lawn before and I’ve worked for clients that had severe infestations, so read my guide where I’ll explain everything you need to know about lawn mushrooms.

Why Do Mushrooms Grow in Lawns?

Mushrooms produce spores that spread all over our gardens and can be found in almost every crevice. Given the right conditions, these spores will germinate and develop into mycelium. 

Just as plants have roots, mushrooms have mycelium.

Under the surface soil in most gardens, you’ll find an entire network of this mycelium which consumes nutrients that allow it to spread.

Given the right conditions (usually in autumn), the mycelium will produce a mushroom, which sprouts through the surface which then goes on to releases spores.

Thus, the purpose of a mushroom is to reproduce.

Mushrooms in Lawns are a Good Sign (Most of the Time)

I’ve met many gardeners who were concerned at the sight of lawn mushrooms; they thought that something was wrong with their lawn and I was often asked questions such as:

• Am I overwatering the lawn?
• Is the lawn too shaded?
• Is there a problem with drainage?
• I’ve just laid turf and mushrooms are now growing, what’s wrong with the turf?
• Will the mushrooms spread and kill the grass?
• Is this a fungal lawn infection?
• What chemicals do I need to buy to kill the lawn mushrooms?

The fact of the matter is that for the vast majority of gardeners, mushrooms in lawns aren’t an issue and are a sign that they have grown a healthy lawn.

Mycelium loves nutrient-rich soil and will grow like crazy in a healthy, well-aerated and well-watered lawn. It struggles to grow in poor, compacted soil.

Based on my many years working in the landscaping industry, I feel you shouldn’t worry if:

• It’s autumn as mushrooms love the warm and moist soil. Also, this time of year isn’t scorching hot, and the sunlight isn’t so strong. I always see mushrooms in my lawn during autumn, and it’s never been an issue.
• You’ve been watering your lawn more than usual, or it’s been raining for several days. Mushrooms thrive in moist, warm conditions, so it’s normal to see them if you’ve been excessively watering your lawn when the soil is warm. I’ve sown lawns from seed in spring and autumn, and I’ve often seen mushrooms popping up due to the extra water I put down.
• You’ve just laid new turf; mushrooms often form in newly laid turf, and it’s nothing to worry about (more about that later).

How to Get Rid of Lawn Mushrooms

I do not recommend the use of any form of fungicide as it will likely damage the lawn, possibly runoff into the surrounding areas and at the least will kill the mycelium that is a perfectly normal and natural part of a healthy garden.

Neither do I recommend vinegar or any “natural” lawn mushroom killer. 

Mycelium is a complex yet crucial part of the ecosystem, and any chemical that kills it will have adverse effects on the garden, so in my opinion, should be avoided. While some mycelium will form mushrooms, most don’t, yet they are all part of a healthy garden ecosystem as they help to recycle nutrients and make them available to other organisms in the garden (source).

If you really want to get rid of lawn mushrooms, you do have a couple of options, and neither involves using chemicals:

• Just put on a pair of gloves and pick them up, I do this occasionally, but usually only if the mushrooms are large.
• I’ve also found that cutting the lawn more frequently is a good way to stop the mushrooms from getting too big.
• Just leave them, they will disappear as the conditions change – mushrooms like moist, warm, fertile ground conditions and from my experience, I know they are very sensitive to weather changes.

Prevention Tips

While it’s perfectly normal to see lawn mushrooms in autumn and when the conditions are just right, you can take some preventative steps if you see an excessive number of mushrooms and you think it’s unusual:

• Drainage – lawn mushrooms love damp conditions and I’ve noticed more of them in the shaded parts of my garden, so if you have known drainage issues in your lawn, mushrooms could be a result of that. I suggest you consider improving the drainage, so the soil isn’t abnormally damp.
• Improve sunlight penetration – mushrooms don’t like strong direct sunlight, so if you see them in the summer, it’s possibly due to excess shade in the garden. I’ve had good results by improving the amount of sunlight reaching the garden, trimming back hedges, overhanging tree branches and even cutting down entire trees.
• Reduce the amount of fertiliser you’re using –  mushrooms and mycelium love fertile soil so cut back on the fertiliser, especially in the autumn when the warm soil and moist conditions are perfect for mushroom growth.
• Dethatch the lawn – decaying matter from cut grass and leaves etc. can leave a layer of thatch near the base of the grass blades, this protects the mycelium from direct sunlight, allowing it to grow and form mushrooms. Thatch also feeds nutrients to the mycelium and mushroom. I always rake my lawn at the end of summer to remove any excess thatch.

Mushrooms growing in the first autumn after we sowed grass in our shaded garden. 

Why Do Mushrooms Grow in New Turf?

You might be surprised to know that mushrooms often grow in newly laid turf, it’s incredibly common.

In fact, I’ve seen mushrooms grow in every lawn I’ve turfed.

But why?

Firstly; the growing conditions for grass are also the perfect conditions for mycelium and lawn mushrooms; warm soil, moisture, aeration etc.

Secondly, do consider that most gardeners will water their new turf daily until the roots have struck into the ground. I’ve found that this excess water is perfect for mushroom growth, as is any feed or fertiliser that was put into the ground before the gardener laid the turf.

One final point on turf mushrooms: As stated at the beginning of this guide, every lawn contains mushroom spores, it’s normal. The process of excavating turf, transporting it and laying it in a new location on freshly disturbed soil will release spores from the turf and the soil in the garden.

These disturbed spores usually lay dormant until the conditions are just right; fertile soil, moisture, warmth etc. 

After a spore germinates, it will grow into mycelium, and I’ve seen mushrooms appear in as little as two weeks if the growing conditions are right.

In a nutshell – it’s perfectly normal to see mushrooms growing in turf; the spores from the turf and your garden plus the watering is what causes them.

A Warning About Fairy Rings

The vast majority of mycelium is healthy for your garden and your lawn, however, a few species are destructive and can damage the lawn and poison the soil.

If you see mushrooms in lawns growing in a circle, they will likely be caused by fairy ring fungi:

Image from Missouri Botanical Garden. Read their guide to lawn fairy rings here.

Image from Garden Seeker. Read their excellent and in-depth tips on getting rid of lawn fairy rings.

Fairy ring fungi are destructive and will discolour the lawn grass within the circle and can even kill it. The fungi are persistent and very difficult to remove; you may need to excavate the turf and soil underneath to get rid of the fungi.

I’ve only seen this a few times and never in a domestic lawn, but in all cases, we excavated the lawn by about 2 foot, doused the area with a liquid fungicide and then after a couple of weeks, we turfed it.

For more information on fairy ring fungi, explore the pages I’ve linked to under the images displayed above.

Conclusion

For the vast majority of gardeners, lawn mushrooms are not something they should be worried about – I get them every year in my shaded garden. Mushrooms thrive in good quality, healthy soil that’s perfect for grass and they love freshly laid turf and all the water that gardeners use to encourage rooting.

Mushrooms will go away on their own when the conditions change, but you can get rid of them by mowing more frequently, raking the lawn or putting on some gloves and picking them up.

You might be able to reduce the number of mushrooms forming by resolving existing issues with lawn drainage, over-watering or poor light. Chemical treatments should be avoided as the mycelium is a crucial part of the garden ecosystem.

Fairy rings are a different beast, and I’ve found it challenging to kill this damaging fungus. You may need to excavate the grass circle to get rid of it.

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