Five Easy Ways To Get Rid of Fungus in Mulch

Did you know that mulch can also create a great habitat for fungi? Many fungi are actually inherent components of this diverse, biological ecosystem. And when fungus develops on mulch, you may want to get rid of some of it. YELLOW FUNGUS is mostly just unsightly but can be left to run its course. The most dangerous type is ARTILLERY FUNGUS, which should be eliminated as soon as practical.

What Causes Fungus on Mulch?

Fungi are fascinating organisms that form as a result of organic breakdown. Many fungi assist in decomposing woody components, whereas others live by eating microorganisms in the mulch. Fungus is not directly caused by mulch. However, under some conditions, mulch and fungus have a symbiotic connection.

Common Fungus on Mulch

  • Mushrooms, which come in many shapes and sizes. Enjoy their beauty, or pick them out.
  • The artillery fungus is a type of mushroom that’s cream coloured with brown cups and black eggs. It’s called “artillery” because its spores are shot out at long distances! Its spores can be nasty to remove because they adhere to other surfaces and leave black spots. Make sure to remove this fungus.
  • Slime molds, often referred to as “Yellow Fungus” or “Dog Vomit Fungus”. Considered unsightly by some, they are typically not a problem, just decomposing matter. Expect them to change colour and eventually disappear.
  • Bird’s nest fungus, which decompose organic matter and can be left alone

Tips on How to get rid of fungus in mulch

Mulch fungus can be hard to eliminate once it has developed. Therefore, it should be addressed as soon as the issue comes up. Many garden experts believe that preventing mulch fungus in the initial time is the best strategy to cope with it.

To stop the fungal growth, some folks simply apply a fresh layer of mulch on top of the existing one. However, this approach frequently fails. This generally results in the fungus sprouting up into the additional layers.

Rake the Mulch 

When you realize that you get mulch fungi, the very first move you should do is eliminate it. This will assist in limiting the transmission of spores and the establishment of new fungal colonies.

This approach works well with mushrooms and toadstools, which are common fungal species that thrive on mulch. After you have eliminated every one of the fungi and nearby mulch, scrape away the uppermost layer of mulch.

The removal of both the fungus and the upper level of mulch will aid in the prevention of future developments of mulch fungal infection. In severe conditions, however, plenty of the mulch may have to be replaced.

Boost the Decomposition Process

Increasing the temperature is one method of killing mulch fungus. The temperature just has to be around 104 degrees Fahrenheit, which translates to 40 degrees Celsius. The good news is that it can be achieved naturally.

To apply this technique, the majority of the mulch must be collected and placed in a sunny location. Hydrate the mulch and then let it sit for a few weeks.

This will initiate the breakdown process. The mulch stack will warm up to levels hot enough to destroy most mold and fungal populations once the process begins.

Raise the pH level

Increasing the pH of the soil might also be a reasonable option for effectively stopping most fungal growths. Because many fungal species, such as artillery fungus and yellow fungus, need somewhat acidic soil, reducing its acidity can inhibit their growth.

This can be accomplished by trying to add liquid lime. It is available in the gardening department of many bigger chain shops.

Simply spray a little amount of this solution onto the soil. Take note not to get it on any vegetation, and do not use it excessively since it might be harmful.

Note that raising the pH level may affect surrounding plants.

Use Fungicides

Mulch fungus can also be treated using fungicides. Note however that for artillery fungus, there are no registered fungicides for treatment.

Bleach can also be used as a fungicide replacement in an urgent situation. If done appropriately, spraying bleach on the soil can destroy the fungus without hurting the vegetation. In reality, watered-down bleach is often used to disinfect and sterilize plant stems and growth media.

Fungicides that are safer and more organic might just be a preferable way. This is because they are relatively safe for both humans and other animals. And, according to studies, they have a lower environmental effect.

Cornmeal and standard baking soda and even toothpaste can serve as organic substitutes. Simply toss cornmeal over the mulch and moisten to activate it. Almost any sort of cornmeal will suffice. Alternatively, immerse one cup in a gallon of water then you can either spray or pour it over the mulch.

Baking soda can also be used in a similar method. In one gallon of water, though, you will only need two teaspoons of it.

Change the Mulch Types

If you have recurring mulch fungal problems, it might be due to the type of mulch you use. Hardwood mulch, in general, is more susceptible to some forms of fungus. As a result, the usage of mulch obtained from decaying or damaged trees should be minimized.

Softwood mulches, such as twigs and other natural matter, are typically considered to be superior. Other solutions to prevent mulch fungus include rotating it often and keeping it from becoming too damp or dry.


Mulch fungus is really not dangerous to plants and occurs naturally as the fungus feeds on microorganisms that disintegrate the mulch. Since fungi accelerate decomposition, disintegrated mulch enhances soil fertility by providing micronutrients to the surrounding vegetation. 

In just about any scenario, the fungus is helpful. Thus most mulch fungus treatments are unnecessary. Some fungi, such as bird’s nest fungi, can even be left on the compost to rot and reintroduced to the soil.

These fungi, however, are sometimes colorful (they originally generate this pigment to ward off predators). As a result, it is preferable to remove them so that youngsters or animals do not consume them.

After the old mulch has been removed, a replacement layer of mulch can be added. It is critical to remember that too much mulch is not a good thing. One to two inches of mulch, according to many specialists, is ideal.

About the Author

I’m Ashley Casey, freelance writer. I’ve written for several online blogs and magazines about home design, construction, gardening tools, and automotive industries.

In addition to my professional life, I enjoy getting outside on my mountain bike, camping with friends or family, beekeeping (though not very successfully), fishing and other hobbies like cooking. My husband is a landscape designer who knows all the best spots to camp near our house in New York’s Hudson Valley so we can explore them together! We live there with our three children and one dog–a rescue mix named Tilly.

Visit a Botanical Garden For Unique Experiences.

More on Gardening Calendar