A Mushroom Invasion: How to Deal With the Fungi in Your Lawn

A mushroom in a lawn.
What You'll Need
Pruning shears
Plug aerator
Nitrogen fertilizer
Dish soap

Although they can be unsightly in a plush lawn, mushrooms can actually be beneficial for grass. Mushrooms feed on decaying material and in doing so, release nutrients into the ground. Where does that decaying material come from? Well, it can be anything from animal waste to sawdust, to dead tree roots or grass clippings. They can also be a sign that your lawn has areas of poor drainage or is under too much shade.

What Is a Mushroom?

It is a fungus. The mushroom that you see (the part above ground) is just the tip of the problem. The visible part of the mushroom is the reproductive part of the fungi. If left in the lawn, the spores from the mushroom will spread to other areas. They can lay dormant for years. Once there are ideal conditions (enough moisture and decaying material) they can pop up and start the cycle again.

The spores are spread by wind, animals and a variety of other methods. Once the spores germinate, they send out feelers called hyphae, which are 12 to 18 inches underground. That hyphae finds another well-suited hyphae and they fuse together and form a kind of knot. That knot grows into a pinhead and then into a mushroom.

Most fungicides have been taken off the market, but if you do happen to find one, remember that spraying mushrooms is only a temporary fix. The visible mushroom itself is not the culprit -- the hyphae is what you need to kill.

Start With a Simple Removal

It is virtually impossible to completely eradicate mushrooms because they can come from neighboring lawns and forests. But there are some ways to control them…at least in your own yard.

The first thing you want to do is to pull them up from the base as soon as you see them pop up. This is a good idea, especially if you have young children or pets that might try to eat them. Wear gloves, because only experts know if they are poisonous or not.

This procedure will only stop the spores from going elsewhere. Less moisture means less mushrooms, but don’t starve your lawn from needed water. There is a delicate balance. By eliminating the organic matter that the mushrooms are growing on, you’ll see a decrease in activity. Start by thatching the area. If that doesn’t work, there must be some other type of decaying matter deeper in the soil.

If you are really ambitious, you can dig down about 12-18 inches, remove all the infected soil, replace with fresh soil and re-seed with grass. However, there are some other avenues to take.

Let in the Light

If the area is too shady, try pruning the trees back to let some light into the area. Then, try aerating the area with a plug aerator to increase drainage.

Try Some Fertilizer

Another method is to spread nitrogen fertilizer (NOT slow-release). The rate at which you apply is one pound of actual nitrogen to 1,000 square feet of lawn. Most non-slow release nitrogen fertilizers are mixed in with other ingredients. If so, then read the bag to see how much nitrogen is actually included. Ammonium sulfate is an example. If you get this kind you will apply it at a rate of 5 pounds per 1000 square feet. Nitrogen increases the rate of decay and will virtually starve the mushrooms out of existence.

Get Out the Soap

A less back-breaking method is the dish soap method. Poke holes around the area of mushroom growth, going as deep as you can (at least a foot into the ground). Pull the visible mushrooms out of the ground. Make a mixture of 2-3 tablespoons of dish soap mixed with two gallons of water. Try not to let it foam. Pour the mixture into the holes you poked. The dish soap will neutralize the hyphae and stop them from growing. The best part is that the soap mixture will not harm the lawn and it will also take care of any unwanted bugs in the area.

Consider Keeping Them

All in all, mushrooms are not a bad thing. Some can be quite beautiful and make for a great photo album. So think before you try to eradicate them from your lawn -- you may want to embrace your natural woodland landscape!