Lawn Mushrooms: 13 Things to Know

Sometimes you’ll see mushrooms popping up on your lawn, much to the dismay of your neighbors and family members. Lawn mushrooms are often a common occurrence in warm climates, where they thrive in moist soil and will sometimes even grow from wood mulch or other organic matter.

But what if these little guys show up outside? Do you need to be worried about them? Let’s take a look at 13 things that might help clear things up for you!

Are Mushrooms a Sign of a Healthy Lawn?

Mushrooms are generally a sign of a healthy lawn and indicate that the ecosystem is working well to decompose dead matter and fertilize the soil with it. Sod expert Greg Nichols has expressed this opinion, and it’s usually what you’d hear from most researchers.

That being said, a sudden overabundance of mushroom caps could suggest that things are starting to die off underneath the lawn, which means that your overall system is possibly starting to die off as well. Watch your lawn closely to make sure that nothing seems to be awry about it.

Nevertheless, you usually don’t have to be concerned if you see many mushrooms pop up right after a good rain.

What Causes Mushrooms to Grow in Grass?

Caps are only part of the mushroom, so when you see these growing above your lawn there’s a good chance that a more sophisticated system has been underneath for a long period of time. Mushrooms grow in the soil because there’s dead material underneath it and they’re feeding on it.

When they do so, they put nutrients back in the soil, which your lawn feeds on in turn. Excessive amounts of water and even shade will help mushroom caps to form at an accelerated rate.

Deceased plant material, like a big tree stump sitting in your yard, can look like a tasty snack to more hardy types of fungus. This too can accelerate the growth of mushrooms.

Should I Remove Mushrooms from My Lawn?

Normally, you don’t have much of a need to remove them from your lawn. If any are just sitting free lying around on it, then you could put them in your compost heap.

These might even sprout in there, which in turn can help to further break down your compost. When you mow your lawn, they’ll usually get chopped down anyway.

Mulch your lawn waste, if this happens, because the mushroom shavings can decompose just as easily as grass clippings will.

Are Lawn Mushrooms Poisonous to People?

Amanitas mushrooms, which are usually notable for their stark white gills, will sometimes grow in lawns and these are quite toxic. Death cap mushrooms belong to this family, and they’re among the deadliest in the world.

Fortunately, you don’t often see them growing outside of certain areas in Europe. Nevertheless, most mycologists will recommend against eating lawn mushrooms unless you know what you’re doing.

Most of these mushrooms have little culinary value anyway, but the fairy ring champion mushroom (Marasmius oreades) is a choice pick for those who enjoy collecting wild mushrooms. You need to be cautious to ensure that you don’t pick any of its imitators, however, all of which have a somewhat different stem.

Are Lawn Mushrooms Poisonous to Dogs?

Nearly any mushroom that’s toxic to a human would be to a dog, so you don’t want your dog experimenting with any of the mushrooms in the yard. Due to their lack of an appealing smell, however, it’s somewhat doubtful that dogs will normally go after them.

The fool’s webcap (Cortinarius orellanus), originally native to Europe, tends to be among the most toxic to dogs in areas where it’s common.

What is the Difference Between Poisonous and Edible Mushrooms?

Overall, poisonous and edible mushrooms only really differ in their production of certain toxins. Their tissues are otherwise nearly identical, and a few toxic mushrooms can be rendered edible by treating them in a certain way.

Some toxic mushrooms have stark white gills or particularly fragile stems, which can help you to identify them.

What Will Kill Mushrooms but Not Grass?

Plucking them or digging them up is a safe bet if you’re sure not to harm the underlying grassroots. Applying a fertilizer that’s rich in nitrogen may also help to get rid of them while keeping the soil balanced for your lawn.

Will Baking Soda Kill Mushrooms in Lawn?

While baking soda will almost surely kill any mushrooms growing in your lawn, its alkalinity is so high that it might also turn your lawn brown. Be careful when applying it for this reason.

Does Dish Soap Kill Mushrooms?

Dish soap isn’t necessarily as strong as baking soda, but it can still help to kill mushrooms in your lawn. You’ll want to avoid getting large amounts of it on the grass, but it’s usually less of an issue.

Pour a few drops into a pint of water and spray it on the mushrooms for best results.

What is the Best Lawn Fungicide?

Usually, the best fungicide is simply running over the mushrooms with a lawnmower, since many people report they grow back anyway. Barring this, you might want to try any of the following:

  • Baking soda and water
  • Dish detergent
  • Cooking oil
  • Pyrethrin leaves
  • Ground limestone
  • Bordeaux mix, which includes copper sulfate
  • Neem oil
  • Copper fungicide
  • Horticultural concentrate
  • Lemon and hot pepper juice

While copper-based fungicides are usually the most effective, they’re also quite expensive and generally the most dangerous. A few things from your kitchen should work without doing too much damage.

Is Liquid or Granular Fungicide Better?

Liquid fungicides will normally penetrate deeper, but they take longer to work. They might also be more resilient against rain than granular ones.

Since you don’t risk getting a granular fungicide everywhere, however, you have less of a chance of causing serious sod damage with one.

When Should I Apply Fungicide to Lawn?

You usually want to apply it when the lawn is dry and it doesn’t look like it’s going to rain soon. Don’t apply it during the hottest time of the day, either, because you risk burning the lawn in that case.

Do You Water After Fungicide?

Some fungicides have to be mixed with water before you apply them, but you don’t need to water immediately after applying these. Others have to sit for a period of time before you can water again.

Always follow the instructions from the fungicide you’re using. If you’re not sure of what to do, then waiting for at least some hours before watering is usually a good idea.