Do you have bad soil? Try Mushroom Compost!

Reader Contribution by Carrie Miller and Miller Micro Farm
1 / 4
2 / 4
3 / 4
4 / 4

When it comes to gardening having the right soil makes the difference between a good growing season or a bad one. I have found the addition of mushroom compost makes all the difference for our vegetable gardens. Our soil consists mainly of heavy clay, making water filtration very difficult. You may think, due to the name that it’s made of mushrooms, but it’s not. Although the recipe changes slightly between mushroom growers it can consist of the following; hay, straw, corn cobs, hulls, poultry manure, horse manure, cow manure, gypsum, peat moss, lime, soybean meal, cottonseed, spent brewers grain, potash, lime, and ammonium nitrate. What you are purchasing is the organic matter that is left after the mushroom farmers grow and harvest their mushrooms. While the mushrooms use some of the nutrients out of the compost, they also leave behind mushroom spores into the mixture, further improving the compost’s nutrients.

So, what is the composting process?

Pure mushroom compost

It’s actually a very in-depth process taking months to complete. All the desired elements are placed into a pile, water is added, and the pile is turned daily for at least two weeks. It then sits for another few weeks turning into a rich chocolate brown material. The third step is pasteurization, which kills off all bacteria and weed seeds. Creating a perfectly clean material. The mushroom spores are then introduced, only further improving the compost. The compost slowly breaks down becoming more soil like. After the mushrooms are harvested the compost is either bagged or hulled away in large truck loads.

How is it used?

Compost once mixed 

The landscaping industry uses the compost in many aspects. Generally being used as a soil additive when seeding or placing sod. The mushroom compost increases water-hold capacity, improves soil quality, and is even known for amending clay soil overtime. Farm Co-Ops and other agricultural business also use the compost on a regular basis. Adding up to a 50% mix into their soil or 25% into container plants. The compost’s PH level typically falls within the neutral range. Commonly staying around 6.6, making it ideal for many applications. The slow release organic plant fertilizer is so packed with nutrients, it’s even said that no other fertilizers will be needed for at least one full growing season.

Gardening with the compost is not even a choice for our farm. Our soil has so much clay that water literally sits upon the grass with nowhere to go. We add manure from the barns, wood ash, sawdust, and straw to our garden every winter. We then add the mushroom compost early in the spring tilling it all together. Our soil becomes a dark, rich, and moist organic garden soil by the time were ready to plant. We also add a small amount around our fruit trees each year, like a mulch, in hopes of enriching the soil.

What to be aware of?

First and foremost, if too much mushroom compost is added to the soil it will become a wet muddy mess. Ask your supplier if the compost contains high soluble salt levels. If it does do not use the compost near blueberry bushes, rhododendrons, azaleas, or other plants that can’t handle the high levels. You are able to purchase bagged versions at some nurseries, garden centers, or Co-Ops but sadly they may not be as good. Why aren’t they as good? Bagged commercial blends are often re-sterilized, in return removing all the amazing microorganisms needed for great soil. Although mushroom compost in made up of all organic matter, some farmers spray their mushrooms with chemicals making the soil no longer organic. If you buy in bulk from landscaping companies they can often tell you if the compost has been altered with chemicals.


Our plants grown with mushroom compost

Around our farm the good strongly outweighs the bad when it comes to using mushroom compost. With Pennsylvania being one of the most popular locations for growing domestic mushrooms, its readily available to us being located in Northeast Ohio. We tried planting gardens on our farm for two years before our neighbor told us their secret weapon to combat the clay soil. The first year we used mushroom compost we produced so many peepers and tomatoes that I couldn’t keep up with canning them. I made spaghetti sauce, chili sauce, sweet salsa, mild salsa, and “make you wish you hadn’t eaten that” hot salsa. I made 25-30 zucchini breads and froze 25 gallons of shredded zucchini off one plant! So, if you struggle with your garden, give mushroom compost a try. 

Homemade blueberry zucchini bread 

Do you want the recipe for blueberry zucchini bread? Click Here

Photos by author.

All MOTHER EARTH NEWS community bloggers have agreed to follow our Blogging Guidelines, and they are responsible for the accuracy of their posts. To learn more about the author of this post, click on their byline link at the top of the page.