How To Get Rid of Mulch Fungus?

Mulch fungus

Did those yellow spots on your mulch get you worried about your soil health? You are not alone! Every year, gardeners and homeowners battle with mulch fungus.

This serious problem can cause a lot of damage to your plants if left untreated. Taking quick action is essential if you see any signs of this fungus. But how to get rid of Mulch fungus?

There are several effective ways to get rid of Mulch fungus. This article will discuss mulch fungus and how to get rid of it. So, read on to learn more!

What Is Mulch Fungus?

Mulch fungus is a mold that grows in moist soils and decaying organic material. It is often seen as dog vomit-like patches of yellow or greenish-brown slimy growth on the surface of the mulch. 

People usually assume mulch fungus is caused by poor drainage, but it’s actually due to the high moisture content in the mulch.

The fungus propagates by releasing spores into the air and then attaching to nearby organic material, where it grows and forms colonies.

Types of Mulch Fungus

Mulch fungus plays a vital role in the garden and is classified into several main types. 

Type #1: Stinkhorns

Source: Wendell Smith

Stinkhorns are a type of fungus that produces a foul smell. The name comes from their shape, which resembles horns and often looks like something from a horror movie.

Stinkhorns build an egg-like structure called an “egg sack” that contains sticky spore-filled slime. This slime is released when the egg sack breaks open and releases a rotten smell.

Stinkhorns are often found in mulch, especially in areas with high humidity.

Type #2: Mushrooms

Mushrooms in mulch
Source: Long Zheng

Mushrooms are another type of fungus commonly found in mulch. They grow in clusters and range in size from tiny to large.

Mushrooms are composed of a stalk and a cap. These caps can be smooth or have ridges, while the stalks are often hollow.

The mushroom’s spores, ranging from brown to yellow or black, give it the color. Mushrooms are generally not harmful but should not be eaten as they may contain toxins.

Type #3: Slime Mold

Slime mold
Source: Wikimedia

Slime mold is a type of fungus that lives in mulch. Slime mold looks like a slimy blob and can range in color from yellow to green or blue.

It feeds on decaying matter and helps to decompose dead plant material.

Although it does not pose any health risks, slime mold can be unsightly when it grows in large clusters.

Type #4: Artillery Fungus

Sphaerobolus stellatus
Source: Björn S…

Artillery fungus is a type of fungus that thrives in mulch. It produces small balls or “spores” that are shot out into the air and can land on anything nearby, including people and buildings.

The spores are sticky and often stick to surfaces like windows or siding. Artillery fungus is challenging to remove, as it can quickly spread between mulch piles.

Type #5: Bird’s Nest Fungus

Bird's nest fungus in mulch

Bird’s Nest fungus is a mushroom growing in wood chips and mulch.

The name comes from its appearance – the mushrooms look like tiny bird’s nests with eggs inside them.

They are typically gray or brown and have a hollow center.

Is Fungus in Mulch Good or Bad for the Garden?

Mulch fungus can be a nuisance, but it benefits your garden’s health. While it may not be beautiful, the benefits of mulch fungus make it an essential part of your garden’s ecosystem.

Here are some of the benefits of mulch fungus to your garden:

  • Mulch fungus helps to keep moisture in the soil and break up compacted dirt, which makes it easier for oxygen and other nutrients to reach plant roots. 
  • The fungi also help to decompose organic matter, creating nutrient-rich compost that benefits plants. 
  • Additionally, mulch fungi can help break down pollutants in the soil and keep disease-causing organisms from taking hold.

Ways To Get Rid of Mulch Fungus

If you are looking for ways to control the spread of mulch fungus, you can do a few things to keep your garden healthy.


Before treating mulch fungus, it is crucial to determine what type of fungus is present. Identifying the type of fungus you have will help determine the best way to get rid of it.

Here is how you can get rid of mulch fungus.

Method #1: Remove Fungus Using Hand

The most basic way to get rid of mulch fungus is simply to remove it yourself using your hands.

Gently dig up the affected area, remove any visible fungus and debris, and then replace the soil with fresh mulch or other material.

Wear gloves when removing the fungus and wash your hands afterward to prevent spores from spreading.

Method #2: Raise the Soil’s pH

Fungus thrives best in acidic soil, so one way to get rid of mulch fungus is to raise the pH of the soil.

You can do this by adding limestone or other materials that will increase the alkalinity of the soil.

Make sure to use only organic materials and follow package instructions for proper application and dosage.

Method #3: Cornmeal


Another way to eliminate mulch fungus is to sprinkle cornmeal onto the affected area. You can spread a thin layer of cornmeal over the top of the mulch.

The cornmeal will absorb any moisture that is present, thus creating a hostile environment for the fungus and preventing it from continuing to grow.

Method #4: Use Fungicides

For more severe cases of mulch fungus, it may be necessary to use a fungicide.

Several fungicides are available on the market specifically designed to eliminate mulch fungus.

Be sure to follow package instructions for proper application and dosage, as some fungicides can harm plants or animals if misused.

Method #5: Change the Mulch Type

If all else fails, you may need to change your mulching material to eliminate the fungus.

Different types of mulch, such as straw or shredded leaves, may be better suited for your particular situation and could help to prevent the fungus from returning.

Method #6: Leave It Alone

Sometimes, mulch fungus can resolve on its own.

If your mulch fungus is not causing significant damage to plants or other vegetation, let it run its course and see if it clears up naturally.

Final Words

Fungi thrive in moist, humid conditions, so keep your mulch dry and well-aerated. You can eliminate this problem by raising the soil’s pH level. You can also use cornmeal or fungicides to remove the fungus.

If you notice any signs of fungal growth, act quickly to treat the area and prevent the spread of infection.

With a bit of diligence, you can keep your garden healthy and free of mulch fungus.

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