What Is Mushroom Compost? 🍄 An Introduction For Beginners

What Is Mushroom Compost 1

Reading Time: 8 minutes 🍃

Mushroom compost might be a great choice for your garden. Some people refer to it as black gold. But what is mushroom compost, and what makes it so special? 

Mushroom compost is an organic, nutrient-rich fertilizer. It is created by mushroom growers and used to feed their crops. Once the mushrooms have been harvested, the compost is packaged and sterilized. The primary benefits are its slow-release nutrients and ability to improve soil drainage. 

With these benefits in mind, it’s common for gardeners to want to try mushroom compost for themselves. But there are a few things to keep in mind to unlock maximum value. Keep reading to learn more about mushroom compost and tips on how to use it in your garden. 

What Makes Mushroom Compost Special? 

This type of compost was made to grow mushrooms. For a strong crop, mushrooms will need to have plenty of organic material to feed on. 

Once the mushrooms have been grown, the compost is gathered up. While it won’t have enough nutrients to grow mushrooms again. But there will be plenty of nutrients for your garden. 

Ingredients In Mushroom Compost

It should be noted that mushroom composts can often vary a little between manufacturers. Often, each mushroom farmer will use slightly different ingredients or change the quantities used. Here are some of the things that you will commonly find in mushroom compost: 

It should be noted that some manufacturers might opt to include lime and potash. It should be noted that these ingredients can raise the pH levels, making the compost more alkaline. As most plants require alkaline soil, this shouldn’t be too much of a problem. But if you are growing varieties that prefer acidic or neutral soil conditions, it might start to cause issues. 

Process Involved with Making Mushroom Compost

While the ingredients might differ a little, most mushroom compost producers will follow the same process. Here are the steps they will use: 

  1. Compost is generated. It can take several months for the items to build up and become sufficiently decomposed. 
  2. Compost is pasteurized. First, the compost is stored at a high temperature, above 160 degrees Celsius, for 30 days. Then, steam will be used to kill any remaining harmful weeds or parasites that might be lurking within the compost. This ensures that it can be safely used to grow food. 
  3. Mushroom spawn is added. After this, it’s common for a layer of sphagnum moss to be placed over the spawn. Sometimes, lime will be sprinkled into the compost mix. Usually, it will take around a month for the mushrooms to grow. 
  4. Mushrooms are harvested. Once the mushrooms have been harvested, the compost will be packed up. It can then be sold as a form of fertilizer for the garden. Depending on the manufacturer, it will be treated with steam before it is sold. This will kill off any bacteria that might be growing in the compost. 

There are some benefits to growing mushrooms before using compost in the garden. This type of compost can be very thick and bulky. The mushrooms can help to break it down, giving it a consistency that is more akin to the soil. This will make it easier to work. 

What Are the Benefits Of Mushroom Compost? 

There are a few things that help set mushroom compost apart; these elements include: 

  • Slow release. This ensures that the nutrients in the compost will be able to sustain the garden for a long time. 
  • Contains plenty of organic materials. This can help increase the amount of microbial activity around your plants, ensuring that the root system can gather nutrients from the soil. 
  • Improves drainage. Because of the amount of straw used in the compost, it will be well-aerated. This ensures that you will be able to boost soil drainage. This is particularly useful in thick, compacted soils. 
  • Increased water holding capacity. This reduces how often you will need to water your plants. This is especially important during the summer months, preventing your plants from dying of thirst. 
  • Protects from hot temperatures.  If the soil gets too hot, it can create problems for the plants. For example, it can cause wilting or stunted growth. The mushroom compost will be able to keep the soil cool to prevent this from happening.
  • It can be used for a wide range of plants. You will be able to use this type of compost with most of the plants in your garden. Though, as we’ll discuss later, there are a few exceptions that you should keep in mind.  
  • It helps to control weeds. Thanks to the high salt content, the mushroom compost will stop weeds from growing in your garden. 

Are There Any Downsides to Using Mushroom Compost? 

While there are plenty of things to admire about mushroom compost, there are a few downsides that you should keep in mind; these include: 

  • Nutrient levels and composition can vary. The exact levels of nutrients in the soil can change depending on the manufacturer that you are using. However, these differences tend not to be too pronounced. 
  • High levels of soluble salts. This can damage some types of plants. We’ll discuss which ones can’t be grown in the compost a little later. 

Can You Make Mushroom Compost at Home? 

Sometimes, buying mushroom compost from the store can be expensive, which is why some people choose to make the compost at home. To make mushroom compost at home, you should follow these steps: 

  • Add a pound of ground corn husks
  • Add a pound of straw
  • Form a tight mound that reaches 70 degrees Celsius (160 degrees Fahrenheit) to destroy any pathogens
  • Leave for a week, adding water to keep the pile damp
  • Add some leaf mold, soybean meal, cottonseed, and any other ingredients that you want to include in your compost mixture
  • Add a few sprinkles of gypsum over the compost, then turn the pile to mix it in 
  • Keep the pile damp and turn it over every few days

You will know that the mushroom compost is ready when it starts to turn a dark brown color. It should also feel crumbly within your hands and have a strong earthen scent. Usually, it can take a few weeks for the compost to reach this point. 

How To Apply Mushroom Compost to Your Garden?

There are a few things that you should keep in mind when you are applying mushroom compost to make sure that you get the most out of it.

What Plants Should You Use Mushroom Compost On? 

The clear majority of established plants will benefit from the use of mushroom compost. Some fruits, like tomatoes, are particularly fond of this compost because of its high calcium levels. 

Which Plants Shouldn’t You Use Mushroom Compost On? 

As we mentioned, mushroom compost has high levels of soluble salt. As a result, there are a few types of plants that can’t work in mushroom compost; these include:

  • Seeds that you hope to germinate
  • Young plants, including seedlings
  • Plants that are sensitive to salt levels

It should also be noted that this compost isn’t suitable for ericaceous plants, which prefer to grow in acidic soil. This is because the high calcium levels can create alkaline soils, which can make it harder for them to absorb nutrients.  

Tips For Adding Mushroom Compost To Your Garden

If you want to add mushroom compost to your garden, there are a few steps that you will need to follow. 

Curing Mushroom Compost

First, most of the mulch that you buy from hardware or landscaping stores will already be cured. But if you are buying fresh mulch from local farmers, you will need to give it some time to cure. This will ensure that the pesticides are washed out of the compost, so it can be used safely. 

To do this, you will need to leave it outside for a few weeks. Rain or snow will ensure that the harmful chemicals get leached out of the compost. 

Reintroducing Microorganisms To Store-Bought Mushroom Compost

If you have homemade mushroom compost, you can skip this step. If you bought from a local supplier and they haven’t sterilized the compost, you can also skip this section. 

As we mentioned, it’s common for manufacturers to sterilize the mushroom compost before they package and sell it. This ensures that it doesn’t contain any potentially harmful bacteria. 

But this can sometimes cause issues. Without these beneficial microorganisms, it will be harder for the plants to access the nutrients within the compost. The good news is that there are a few ways that you can re-introduce the microorganisms; these include: 

  • Watering with worm juice. Worm juice is the name given to the materials produced by worm farms. This is rich in nutrients and teeming with microorganisms making it a great addition to your garden; after adding the mushroom compost, water with worm juice. 
  • Mix it with regular compost. If you make your own compost, it will have plenty of microorganisms. Simply mix your mushroom compost in. You can use a ratio of one-part regular compost to every four-parts mushroom compost. 

Using The Mushroom Compost in Your Garden

Once you’ve done this, you can incorporate the mulch into your garden. Here are some guidelines that you should keep in mind: 

  • Apply in summer or spring. This is when the plants will most need the nutrients. Plus, it’s easier to work the compost when it’s dry.  
  • Flower and vegetable beds. In this case, you will only need a thin layer of compost. Because of this, you will need to apply one to three inches of mulch. Mix it into the top layer of soil. 
  • Container plants. This can be a good way of providing nutrients and improving drainage. Because of this, you will need to use a ratio of 1:4 between mushroom compost and potting mix. 
  • Trees and shrubs. In this case, you will need to use the mushroom compost as a form of mulch. You can layer it around the base of the tree or shrub. Often, it will only need to be a few inches deep. 

If you are looking to add mushroom compost before you plant, it’s best to mix it thoroughly into the soil. This ensures that the salts from the compost don’t harm the plants. After you have added the compost to your garden, it’s best to water it thoroughly. 

Because the nutrients in mushroom compost are released slowly, you should only need to replace it once a year. It’s best to do this at the start of spring, just when the temperatures are starting to rise. This is the time of year when plants are growing most strongly and will need the nutrients from the compost the most. 

Other Uses for Mushroom Compost

While it’s most common for mushroom compost to be applied to your garden, there are a few other ways that you can use it in your garden. These include: 

  • Soil additive. If you have thick, clay soil, it can make it tough to plant a garden. The root systems will often find it harder to penetrate, and the ground will retain too much water. Mixing some mushroom compost into the soil can help you solve this problem. Furthermore, it can help raise the pH level if you have slightly acidic soils. You will often need to mix a few inches of mushroom compost into the topsoil. 
  • Improving your lawn. Mixing mushroom compost into your grass serves two purposes. First, it gives the lawn plenty of nutrients, so the grass will grow strongly. Secondly, the salts will help you naturally control the spread of weeds. 

Final Thoughts

To help your garden thrive, mushroom compost is a great selection. It has plenty of nutrients, can improve drainage, and will be suitable for most plants. Even better, it’s relatively easy to make at home, or you can find it in a landscape center. Plus, it can be used in most of your garden, including the lawn. 


Was this article helpful?

Team Leafy

Hi! Thanks for reading our article, we hope you enjoyed it and helps make your garden grow greener. If you found this article helpful, please share it with a friend and spread the joy. Plant small. Grow big!

Recent Posts