Benefits of Mushroom Compost: Gardening With Mushroom Compost

Last updated on October 21st, 2023 at 10:26 pm

Mushroom compost is an excellent addition to the garden soil. Organic gardening with mushroom compost can be done in many ways and offers many benefits to the garden.

What is mushroom compost?
Mushroom compost is a type of slow release organic plant fertilizer. Compost is made by mushroom growers using organic materials such as hay, straw, corn cobs and husks, and poultry or horse manure.

Because the process of growing mushrooms varies slightly from grower to grower, mushroom compost recipes may differ here and there. For example, additional materials such as gypsum, peat moss, lime, soybean meal and various other organic elements can also be added to the compost.

Once the fungus is mixed into the compost, it is steam pasteurized to kill weed seeds and any other harmful agents. A mixed layer of sphagnum moss and lime is covered on top of the pile for the mushrooms to grow.

Mushroom composting takes about three to four weeks to process, during which time it is closely monitored by mushroom growers to maintain proper temperatures. Once the process is complete, the leftover compost is disposed of and sold as fertilizer.

Mushroom Compost for Gardening
Mushroom compost is usually sold in bags labeled SMC or SMS (spent mushroom compost or spent mushroom substrate). It is available at many garden centers or from landscape supply companies. Mushroom compost is also available for purchase by the truckload or bushel, depending on its use in the garden.

There are several uses for mushroom compost. It can be used as a soil amendment for lawns, gardens and potted plants. However, this product should be used with caution because of its high levels of soluble salts. These salt levels can kill germinating seeds, harm young plants and damage salt-sensitive plants such as azaleas and rhododendrons.

Benefits of mushroom compost

However, the beneficial uses of mushroom compost far outweigh the drawbacks of high salt levels. This type of compost is reasonably inexpensive. It enriches the soil and provides nutrients for healthy plant growth. Mushroom compost also increases the water-holding capacity of the soil, which reduces your need for water.

Mushroom compost is suitable for most garden plants. It supports various types of plant growth, from fruits and vegetables to herbs and flowers. For best results when gardening organically with mushroom compost, mix it thoroughly with the garden soil before planting or let it sit over the winter and apply in the spring.

How to use mushroom compost

Working compost into your garden improves soil texture and drainage and adds nutrients to the soil. If used as a mulch, compost also controls weeds and helps the soil retain water in dry weather. Mushroom compost is a nutrient-rich mixture of straw, peat, gypsum and other organic materials. The pH of mushroom compost is in a range that will help most plants thrive, says MushroomCompost.org, and it has the rich, dark appearance of healthy soil, making it an attractive compost choice for any gardener. Mushroom compost can be used as mulch or worked into your beds as a soil amendment.

When mulching, you should use between 1 and 3 inches of mushroom compost. Use 3 inches of compost for better water retention and weed control. When using mushroom compost as a soil amendment, plan to work in a 3-inch layer if you have sandy soil or a 1 to 2-inch layer if you have clay soil. There are many online calculators to help you figure out how many cubic feet of compost you will need. When working the compost into the soil, work carefully around shrubs or trees to avoid nicking their bark.

Measure the length and width of the areas you want to mulch or modify. For areas that have irregular borders, measure the areas at their widest and longest points. Epic Gardening suggests using no more than 50 percent mushroom compost and, in containers, using 25 percent or less.

Add up all the widths you measured, round up to the nearest whole foot and record that number. Add up all the lengths you measured, round up to the nearest whole foot and record that number. For example, if the total width is 3 feet 7 inches and the total length is 9 feet 10 inches, round up to 4 feet and 10 feet respectively.

Multiply the total width number by the total length number to determine the total area that needs to be mulched. In the example, the total area is 40 square feet (4 x 10 = 40).

Calculate the cubic feet of mushroom compost you need by multiplying the total area by how deep you want your mulch to be or how much you want to work as a soil amendment. The depth number should be in feet. In the example, if you want to add a 3 inch layer of mulch, you will need 10 cubic feet of mushroom compost (3 inches equals 0.25 feet, so 40 x 0.25 = 10).

Buy your mushroom compost from a reputable dealer. Many offer to have it delivered for a small fee, or you can load your own truck. Although you can mulch or amend at any time of the year, the best time to do this project is in the spring or fall.

Shovel small loads of mushroom compost into the wheelbarrow. Roll it over the areas you want to mulch or amend and dump the compost in. You can choose to roll and dump all the compost before spreading it, or dump and spread each load as you go. If someone is helping you, they can spread while you deliver the loads of compost, or vice versa.

Spread the compost over the area you are working on with a rake to the desired thickness. If you’re using it as a mulch, you only need to spread the compost. If you are using the compost as a soil amendment, use a garden hoe to work the compost into the soil.

What is compost?
Compost refers to organic material that has been broken down to provide nutrients to the soil during the growing season and at the same time, minimizes food waste. This step, called composting, is a relatively easy process to perform, assuming you know which of the list is recommended for the process.

Although composting is equivalent to minimizing food waste, some things are strongly discouraged from being part of the process, such as animals and dairy products. Animal products take time to decompose, so they can serve as a breeding ground for microbes, which causes disease.

Therefore, it is best to stick with plant and fruit products – mushroom compost, for example.

Mushroom compost is a compost mixture that is usually made up of straw, hay, gypsum and chicken or horse manure used to grow mushrooms. It is sometimes called spent – meaning that the mushroom grower has used it several times. Compost is rotted organic material that is usually made up of decaying plants and manure, and used to enrich soils. Gardeners can purchase mushroom compost at their local lawn and garden store if they wish to add it to a garden as fertilizer.

Compost is made by mixing various plant materials with manure. As the organic material decomposes, the bacteria in the material will begin to multiply and the temperature inside the compost pile will gradually begin to rise. Once the temperature reaches and exceeds 160° F (about 71° C), all weeds and pathogens are killed. It usually takes about 30 days for the mushroom compost to be ready for use.

As an added precaution, the mixture is pasteurized before the mushroom spores are added. The spores are very similar to plant seeds, but do not carry food resources like seeds. These spores will turn into mushrooms in the compost, and the same mixture can be used up to three times before being discarded. Mushroom growers often have a recipe for their mushroom compost to ensure that they produce a consistent product. This consistency also makes using spent mushroom compost a desirable product for gardeners.

Gardeners should be careful with some types of mushroom compost, however, as they may contain a large amount of soluble salts, which can damage or kill plants. The mixture should be used with caution and moderation. It may also contain fungicides and pesticides, which may be of concern to organic gardeners. Organic farming and gardening are free of chemicals and pesticides.

People can easily make their own compost using organic food scraps or plant material. Organic materials can be placed in a pile or an outdoor garbage can. There are pre-made compost bins available for purchase that turn the materials so that the contents can be mixed. These bins can have an open or closed design. There are even sealed containers for the kitchen counter, so that cooks can throw compostable items into them while they work.

Compost is generally used to improve the structure and nutrient quality of the soil. It can be applied as a mulch or mixed in before planting seeds or seedlings. Mushroom compost and homemade compost can also be used to make compost tea. This is also used as a fertilizer, or as a preventative to protect plants from disease, and is made simply by soaking compost in water for up to five days. It is then sprayed on the soil or non-edible parts of the plants.

How do I use mushroom compost?
For flower beds and vegetable gardens, dress with the compost or grow about three inches of compost in the top six inches of fairly dry garden soil. For containerized plants, it should only be about a quarter of the volume of soil in the container.

However, mushroom compost is not suitable for all plants because it is rich in soluble salts and other nutrients. These can kill germinating seeds and harm salt-sensitive plants, including rhododendrons, azaleas, camellias and other members of the heather family (OSU). It should also not be applied to young plants as they are particularly sensitive to high levels of salts and ammonium.

You can make compost tea to use as a liquid fertilizer/leaf spray by mixing one part compost with four parts water. The “tea” will contain an abundance of beneficial microorganisms, including bacteria, fungi, protozoa and nematodes. This concoction will help your plant survive any pest attacks or diseases.

Is mushroom compost good for tomatoes?

Yes, it provides calcium and increased alkaline matter to the soil, which helps ensure that tomatoes do not fall victim to blossom end rot. It also helps the soil retain water to help tomato plants thrive.

Are there any plants that don’t like mushroom compost?

Dr. John Hart (Oregon State University) points out that it might be “too much of a good thing” for germinating seeds, seedlings and young plants. When using it on young plants, he recommends mixing it with garden soil.

Most plants generally grow well in a soil pH range of 6.0 to 7.0. The average pH of mushroom compost is 6.6, making it an ideal fertilizer for most plants growing in a typical range.

What are the tips for planting in mushroom compost?

This compost contains some chalk and is alkaline in nature. Before applying it, remove any visible chalk. It is also advisable to mix it with well decomposed manure and/or traditional finished compost.

What are the benefits of mushroom compost for vegetable gardens?

This compost is an excellent fertilizer and soil builder for vegetable gardens. It contains a range of macronutrients and micronutrients that make it an excellent soil conditioner.

It can improve overall soil structure, provide key nutrients to plants, increase plant root structure and improve soil water conditions. In addition, its pH is relatively balanced, so available nutrients can be easily absorbed by most plant roots.

It is especially beneficial in raised beds growing cabbage, broccoli, cauliflower, Brussels sprouts and kale.

What are the benefits of mushroom compost tea?
Mushroom compost tea is an excellent liquid fertilizer to protect plants from disease and bacteria.

Mushroom compost vs. cow manure: which is better for my soil?

Both fertilizers are excellent sources of soil nutrients. However, unaged cow manure that has not been composted contains a risky amount of pathogenic bacteria, ammonia and weed seeds. You should definitely (at least partially) compost cow manure before using it in your garden.

On the other hand, mushroom compost (pasteurized substrate) does not present these problems. Ultimately, it all depends on what you have access to and whether you plan to compost.

Allowing cow manure to age is certainly an easier process than making mushroom compost at home. On the other hand, if you are considering purchasing either option, commercially available products are very comparable in price at about $3.00-$5.00 for a 40 lb bag.