Can You Put Mushrooms In The Compost Bin (benefits and drawbacks)

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Can you put mushrooms in the compost bin? If you’ve noticed the mushrooms in your refrigerator are past their prime, it’s a question you may have pondered and a decision that may have significant consequences for your green space. Do you simply toss them in the trash or reuse them to improve your garden? Surprisingly, as you choose a more sustainable and eco-friendly lifestyle, composting mushrooms is one easy way to do it because it’s so easy and supports effective waste management in your own home.

Mushrooms contribute valuable nutrients (nitrogen, potassium, calcium) to your compost and enrich your soil and garden plants. Chopping mushrooms into smaller pieces speeds up decomposition and prevents contamination issues. Opt for varieties like button and oyster for better composting.

overhead view of small batch of raw white button mushrooms in kitchen

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In this informative article, we’ll cover some exceptional tips for adding or incorporating mushrooms into your homemade compost. We’ll also provide some best practices to ensure they break down effectively and contribute to a rich, fertile compost your garden plants will love.

Remember, whether you have experience composting or are new to the practice, the following sections will equip you with the knowledge to make the most of your unused mushrooms.

Humble Highlights

  • Discover the surprising advantages of tossing mushrooms in your backyard compost AND save time by knowing the best ones to add so you can boost your pile’s effectiveness! 
  •  Save time with these 5 insider tips when adding mushrooms to avoid potential challenges within your compost heap so you know what to expect AND the simple pros and cons of incorporating them! 
  • Stop wondering if cooked mushrooms can be added to your compost and know when and how to mix them into your heap for the best results so you can provide for your green garden friends while reducing household waste!  

Benefits Of Using Mushroom Compost For Your Plants

Mushroom compost enriches compost in several ways. Mushroom growers have observed that incorporating mushrooms already cooked into the compost bin or heap helps reduce the likelihood of unpleasant odors and facilitates faster decomposition.

how to use mushroom compost

Adding mushrooms into your organic mix introduces essential fungi that help speed up the breakdown of organic matter. These fungi work symbiotically with bacteria to create a nutrient-rich compost. In fact, when you add your mushroom scraps, you’re not just disposing of waste but also enhancing the microbial activity within your pile. 1

Can You Compost Mushrooms: Preparing Mushrooms For Compost

Generally, if you have whole mushroom pieces, it is best to chop them first before adding them to your backyard compost pile. These smaller pieces will ultimately increase the surface area, accelerating decomposition. You’ll also want to ensure the mushrooms are free from oil and dressing, as these can lead to anaerobic conditions in your compost bin. 

plants that don't like mushroom compost

To safely incorporate mushrooms into your organic mix, you must also consider their water content. Wet shrooms break down faster, contributing to the moisture levels of your composting heap. Although mushrooms provide excellent compost nutrition, you’ll want to avoid adding too many at once, which might create an imbalance in your compost mix. 2

Potential Issues And Solution When Adding Mushrooms On Your Compost Pile

You’ll need to address a few potential issues when you add your mushrooms to your compost pile to ensure a healthy balance of compost. 

what do you use mushroom compost for

  • Toxic mushrooms can also harm your plants. Avoid adding poisonous mushrooms like Amanita Phalloides (Death Cap), Gyromitra Esculenta (False Morel), Galerina species (Funeral Bell), Cortinarius genus (Fool’s Webcap), or Inky Caps (Tippler’s Bane) to your compost pile, as they can pose serious health risks to your plants if mistakenly included.
  •  If your compost is too wet, it can hinder the decomposition process. If you see fungi in your compost, this might indicate overly wet conditions, and you’ll want to amend your pile accordingly to get it back on track. 3
  •  To maintain the correct moisture levels, turn your compost pile regularly (at least once weekly). This simple step that only takes a few minutes aerates the pile, promotes better drainage, and helps your pile throughout decomposition. 
  • Ensure the mushrooms you add are adequately mixed with other compost ingredients to avoid attracting pests such as fruit flies or rodents. As a good rule of thumb, you can incorporate mushrooms in the center of your pile to disguise their odor and deter any curious visitors.
  • Always dilute the compost by adding water before use to prevent harm to plants and seedlings. Diluting your compost helps reduce harmful compounds and excessive nutrients and ensures even nutrient distribution, preventing localized over-concentration that could harm your plants’ roots.

can you put mushrooms in compost

Mushrooms Growing In Compost: Is Fungi In Your Compost Pile Good

Having mushroom fungi in your compost pile can make things interesting. It can bring both good and bad effects to how your compost turns out in the end. Generally, mushrooms will appear when you have a balanced organic mix. While the presence of mushroom fungi signals an active, fertile environment, it’s still crucial for any backyard gardener to weigh the pros and cons. 4

Here’s a list of pros and cons when mushrooms appear in your pile.

Natural decomposers of organic matterSlower composting process when used excessively
Enhanced compost pile aerationCompetes with other microorganisms and can affect microbial diversity along with the overall decomposition rate
Nutrient recyclingMushroom spores can lead to unwanted mushroom growth once the compost is spread in the garden
Indicator of well-balanced composting

Humble Tip:
A well-balanced compost includes various organic materials, such as kitchen scraps, yard waste, and other plant matter. Ensure that mushrooms are just one component of this mix rather than the dominant one.

Don’t rely solely on mushrooms as your compost input. Instead, use them as part of a diverse range of compostable materials. This diversity helps maintain a balanced carbon-to-nitrogen (C:N) ratio, crucial for efficient decomposition.

Composting with mushrooms can make a big difference in the quality of your compost and garden soil. That’s because mushrooms already contain fungal spores and activity that cause the microorganisms that break down your compost happy. Check out this informative video below to discover why mushrooms might be the missing link you’ve been looking for to amend your compost pile!

Cooked Mushrooms In Your Compost

When cooked mushrooms are composted, managing the additional moisture they may introduce is crucial. You can add them to the center of a hot compost pile to ensure that they decompose effectively and don’t turn your organic mix anaerobic (little to no oxygen presence). The elevated temperatures of hot composting will then help accelerate the breakdown activity.

are mushrooms good for compost

A hot compost pile is a composting method that generates and maintains high temperatures through microbial activity. The pile comprises organic materials like kitchen scraps, yard waste, and other compostable materials with elevated temperatures reaching between 135°F and 160°F (57 °C and 71 °C). 5

Humble Tip:
It’s imperative to avoid excessive oil content when incorporating mushrooms into your compost, as this can inhibit or hinder the breakdown activity of organisms and disrupt the balance of your organic mix.

Remember to ensure that mushrooms in your compost are non-toxic and monitor for any unwanted spore growth throughout. Additionally, water your compost regularly for proper aeration.


Benefits Of Mushroom Mycelium: Enhances Composting Process

Incorporating mycelium (the vegetative part of the fungus) from your edible mushrooms into your compost can significantly boost its decomposition rate and nutrient profile. As a living fungus, it acts as a natural accelerator that efficiently breaks down organic materials. 

When you add your mushroom spawn (mycelium), you’re introducing a powerhouse of decomposition. It secretes enzymes that help digest organic matter and spreads through the substrate, unlocking nutrients like nitrogen, potassium, and copper, vital for plant growth. 6

Humble Tip:
Always use spent mushroom substrate (SMS) to avoid contamination. SMS is the leftover material from mushroom cultivation, typically a mix of biodegradable materials like straw and sawdust used for mushroom growth. It enriches compost with nutrients, enhances microbial activity, and improves compost quality.



Whether fresh or cooked, mushrooms add valuable nutrients to your backyard compost. Interestingly, mushrooms remain the only good source of selenium among produce, despite the majority of selenium being derived from grains or animal-based sources.

For the best compost results, add only edible, wild, or commercially cultivated mushrooms, such as portabella or cremini, in your compost. These select species provide essential elements such as nitrogen, phosphorus, and potassium, particularly beneficial for plant growth.

Be cautious with invasive or unchopped mushrooms as they may spoil parts of the compost, making it unsafe and even toxic for your garden plants. Consider chopping your mushrooms into smaller pieces for faster decomposition within your pile, and turn your heap frequently to incorporate the ingredients and encourage the microorganisms to work hard on your behalf. Remember, your efforts help nurture the environment one small step at a time, creating a cycle of growth that benefits us all.

We’d love to know if you currently toss mushrooms in your backyard compost. If you do, let us know if you’ve noticed a difference in the quality of compost you add to your garden by dropping a line in the comments below!


  1. American Mushroom Institute – Mushroom Compost
  2. Penn State University – Spent Mushroom Substrate
  3. Missouri Department Of Natural Resources – Homeowner’s Composting Guide
  4. Oregon State University, OSU Extension Service – Do The Rot Thing – Choosing And Using A Composting System
  5. United States Environmental Protection Agency – Preventing Wasted Food At Home
  6. Wikipedia – Mycelium

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