Unlike the name suggests, mushroom compost does not contain any mushrooms—it is a by-product from mushroom farming; the growth medium of mushrooms is removed after the mushrooms are harvested. The more apt name for it is mushroom soil.
Just like regular compost, mushroom compost is often touted as black gold. When used properly it acts as a plant fertilizer and soil amendment to benefit your plants.
Manure Compost vs Mushroom Compost Which Is Better for Your Garden?
When it comes to nourishing your garden soil, two of the most popular organic amendments are manure compost and mushroom compost. Both can provide key nutrients and improve soil structure. But is one better than the other for your specific gardening needs? In this comprehensive guide, we’ll examine the pros and cons of manure compost vs mushroom compost to help you decide which is right for your garden.
What is Manure Compost?
Manure compost is made by composting animal manures such as cow, horse, sheep, goat, chicken, etc. As the manure breaks down, it releases essential macro and micronutrients that plants need to thrive. These include nitrogen, phosphorus, potassium as well as many trace minerals.
Some key benefits of manure compost include:
- Rich in nutrients – contains higher levels of NPK than mushroom compost
- Improves moisture retention and drainage
- Increases microbial activity and populations
- Provides organic matter to improve soil structure
- Prevents nutrient leaching
However, fresh or raw manure can damage plants, so it must be aged properly before using in the garden. And manure compost can have higher salt content as well as potentially contain weed seeds or pathogens if not thoroughly composted.
What is Mushroom Compost?
Mushroom compost, also called spent mushroom substrate, is leftover material after mushrooms have been harvested. It is typically composed of straw, hay, horse manure, peat moss, and gypsum.
Some advantages of mushroom compost:
- Neutral pH – good for plants needing balanced pH
- Weed-free and pathogen-free
- Improves soil structure and drainage
- Contains mycorrhizae fungi to help plant nutrient uptake
- Lower salt content than manure compost
On the downside, mushroom compost generally has lower nutrient levels compared to manure compost. It also tends to be more expensive and less readily available than manure compost.
Key Differences in Nutrient Levels
When evaluating manure vs mushroom compost, it’s helpful to look at the primary macro-nutrients nitrogen (N), phosphorus (P) and potassium (K).
Typical NPK levels:
- Composted cow manure: 0.5-2% N, 0.5-1% P, 0.5-1% K
- Composted horse manure: 0.7-2.7% N, 0.3-0.9% P, 0.6-1.8% K
- Mushroom compost: 0.5-0.7% N, 0.3-0.4% P, 0.2-0.4% K
As you can see, manure compost generally contains higher percentages of the major nutrients plants need for healthy growth and fruiting.
Evaluating Costs
When weighing the costs of manure compost vs mushroom compost, manure compost tends to be more budget-friendly. Mushroom compost is typically priced at $15-30 per cubic yard, while manure compost ranges from $10-20 per cubic yard.
If sourcing manure locally, costs may be even lower. However, mushroom compost is sold pre-packaged so there is less labor involved in preparing it for use.
Assessing Availability
Manure compost enjoys wider availability than mushroom compost. It can be sourced from local stables, farms, or produced at home if you have access to animal manures. Mushroom compost is harder to make DIY, so it needs to be purchased.
While most garden centers carry both, mushroom compost may sell out quickly given its rising popularity. If mushroom compost isn’t readily available in your area, manure compost may be a more convenient choice.
Choosing Between Manure and Mushroom Compost
Now that we’ve explored the key differences, how do you decide what’s right for your garden? Here are some factors to consider:
Choose manure compost if:
- Your garden needs a nutrient boost
- You want to improve moisture retention
- Your plants prefer slightly acidic soil
- You have ready access to quality composted manure
Choose mushroom compost if:
- You need a balanced, neutral pH
- Your plants are salt-sensitive
- You want a weed-free, pathogen-free amendment
- Local manure sources are limited
For gardens with average soil, a blended approach using both manure and mushroom compost may be beneficial. Manure compost provides nourishment, while mushroom compost enhances soil structure.
Follow Composting Best Practices
Whichever compost you select, following best practices is key:
- Allow fresh manure to age 3-12 months before using
- Thoroughly mix compost into soil – don’t leave in clumps
- Apply 1-3 inches per 100 sq ft of garden space
- Reapply annually or as needed based on soil tests
With the right compost choice and proper application methods, you’ll be rewarded with healthy, productive garden beds! Test different composts and find the best fit for your unique conditions.
How Mushroom Compost Is Made
:max_bytes(150000):strip_icc()/Gettys-455624383-08d613bcfb4a4ea685887f2349c72c22.jpg)
When the substrate in which mushrooms are grown is no longer suitable, it is still valuable for gardeners.
The mushroom substrate contains hay, straw, poultry or horse manure, and crop residues such as corn cobs and cocoa shells. The exact composition of the growth substrate varies from grower to grower. The substrate is composted for about 30 days at 160 degrees to kill weed seeds, pests, or disease pathogens. Additionally, it is steam-pasteurized at about 140 degrees F to kill any pests and pathogens that could cause surface diseases. Then the medium is inoculated with mushroom spawn, or mycelium, and covered with sphagnum moss and ground limestone to support the mushroom growth.
After mushrooms have been harvested for about three to four weeks, the medium’s ability to sustain mushroom growth is exhausted and replaced with fresh mushroom soil for a new batch of mushrooms. The substrate is then sold in bags or bulk, often labeled as SMC (Spent Mushroom Compost) or SMS (Spent Mushroom Substrate).
Mushroom Compost vs. Regular Compost
:max_bytes(150000):strip_icc()/SPR-what-is-mushroom-compost-6665515-01_3413-97be9479b42142ba944b64e2c7d5d4d3.jpg)
Mushroom compost and regular compost from your compost heap or composter are not interchangeable due to key differences.
All compost varies in composition, unlike commercial fertilizer, where the label gives a detailed analysis of the nutrients. Mushroom compost has already been used as a growing medium, which means it generally contains less nitrogen than regular compost. It may be a good choice for soil already rich in nitrogen since excess nitrogen leads to overgrowth of foliage and stunted roots.
Mushroom soil also contains more calcium than regular compost due to the addition of chalk. Plants like tomatoes do well in a calcium-rich soil which helps tamp down blossom-end rot. However, calcium increases the soil pH level which is problematic for plants like blueberries that need acidic soil.
Cow Manure Compost vs Mushroom Compost – Which One Is Better? (Which is Ideal For You?)
FAQ
Which is better, composted manure or mushroom compost?
The advantages of using mushroom compost are that the extra “hot” material that they add to this type of compost (whether it is cow manure, chicken manure or other) adds more nitrogen to your garden, and it also kills any weed seeds and even diseases that might have been found in the plant matter.
What are the disadvantages of mushroom compost?
When should you not use mushroom compost?
Mushroom compost use should be avoided where ericaceous plants such as rhododendrons, camellias, azaleas and heathers are being grown, as these plants need acidic growing conditions and are chalk-hating.
What plants do not like mushroom compost?
Mushroom compost, while beneficial for many plants, can be detrimental to certain types, particularly those that prefer acidic soil or are sensitive to high salt content. Specifically, plants in the Ericaceae family, like azaleas, camellias, and rhododendrons, as well as blueberries, should be avoided as they dislike the high pH and salt levels of mushroom compost.