Mushroom compost is a pretty good product. It can give a lot of water to your garden or lawn before you plant some flowers, etc…
However, there are some plants that do not respond to that which mushroom compost has to offer.
Not all plants like mushroom compost. For example, the whole family of ericaceous plants tend not to thrive on mushroom compost due to its alkaline structure.
It does not have the acidity needed for these types of plants to flourish. While mushroom compost is good on bushes, trees, perennials, and vines, it is not good for every type of plant.
In this blog we are looking at 10 plants that do not like mushroom compost. We’ll also take a look at some facts about mushroom compost and how it is best used.
Keep reading to learn more about this well known type of compost and what it has to offer and why it doesn’t work for some plant.
About Mushroom Compost
Mushroom compost comes from mushroom farms.
It’s what leftover after harvesting the mushrooms. That is also why it gets called “spent mushroom compost.”
You can think of mushroom compost like a conditioner. Just like we put conditioners in our hair to retain moisture and nutrients, mushroom compost does the same for soil.
It allows soil to hold more moisture for plants to use while providing nutrients those plants need.
Mushroom compost is typically very high in alkaline which means that using it can neutralize acid soil.
Important to Know: Plants that need a pH below the alkaline level will not succeed in mushroom compost. Mushroom compost has a pH between 6.0 and 7.0+.
How to Use Mushroom Compost to Plant
Mushroom compost can be used in a couple of ways, and the first use is to work it into your soil before you plant.
For example, if you want to create a vegetable garden, you could certainly work it into the soil.
It can also be used in the layer of soil you put down before sod goes over it.
Mushroom compost also works wonderfully in perennial beds. You can put down a nice 3″ thick layer of mushroom compost over your annual or perennial bed.
Then you can scoop down for about 6 inches for planting. This will give you the best results.
When you use mushroom compost for lawns, you won’t need to be adding anything more for the rest of the season. Just keep watering and dealing with the weeds.
To take the most advantage of mushroom compost with any plant, try to place the compost right at the base of the stem to allow the plant to absorb the nutrient composition easily.
You can also use mushroom compost for potted houseplants. You will not need too much.
You can just put a light layer of mushroom compost on top of the soil.
Just make sure there are enough drainage holes in the bottom of the pot!
Ericaceous Plants Dislike Mushroom Compost
Ericaceous plants are acid-loving plants.
Mushroom compost is high in alkalinity. That means it has a good ability to neutralize acids.
Ericaceous plants love the acids in some soils.
Mushroom compost would take away something absolutely necessary for their survival.
1. Cranberries
Cranberries are acid-loving plants, so they prefer soil with a pH between 4.0 and 5.5, for best results.
Make sure to level or raise the grow bed so you will have drainage and control of the acid level.
Don’t use mushroom compost for this plant! Happy gardening.
2. Blueberry
Blueberries have an acidic soil requirement.
Blueberries grow in the shade but prefer the sun.
You can expect great results with regular irrigation and soil moisture consistently maintained.
It’s a good idea to include peat moss when planting blueberries to provide a sound growing environment.
No mushroom composting here, or no blueberry plant will exist.
3. Azalea
Azaleas mostly die by malnutrition by being planted in alkaline soil.
Mushroom compost would just kill this plant. Azaleas need a pH of about 5.5 to 6.2.
Without the acid the leaves of the bush will start to turn yellow.
And eventually the bush will die out.
4. Hydrangea
Hydrangeas love mushroom compost.
They’re fine in acidic soil or alkaline soil. The flowers colors change depending upon the pH of the soil.
You can grow hydrangeas in acidic soil to get blue flowers.
Mushroom compost makes the pH level too low so you might see pink flowers.
5. Aster
Asters grow best in neutral to acidic soils.
The pH will not need to be excessive- stay between 5.8 and 6.5. Asters need moisture, but not too much.
Once they mature, about once a week is fine.
6. Fern
Ferns can make their home in alkaline soil but grow best in acidic soils.
Ferns also prefer moist soils. You can neutralize some acids and ensure the pH is around 5.0 to 6.0 if your soil is very acidic by using mushroom compost.
Mushroom compost also retains moisture for the fern plant.
7. Juniper
Juniper trees and shrubs accept a variety of soil types.
They typically prefer slightly acidic soil. In addition, they require good drainage.
Overwatering junipers leads to root-rot.
For the best results, keep the pH level over 5.0.
8. Gardenia
Gardenias like a low acid level for their best growth.
The pH level should range between 5.0 and 6.0. If you are planting them near the foundation of your house, the level of the acid is most likely too high there.
If that is the case, you could use a little mushroom compost to neutralize the acid.
If not, simply plant them at a distance from the building.
9. Japanese Maple
Japanese Maples are pretty low-maintenance plants.
Japanese Maples will grow well in loamy or sandy soil, and prefer slightly acidic soil for optimum growth.
High alkaline soils, such as soils that have been mixed with mushroom compost, create poor growing conditions for Japanese Maples.
10. Holly
Holly plants like acidity levels.
Don’t use mushroom compost for moisture retention with holly. Holly plants are available in alkaline soil, and they are typically yellowish in color.
If you see your holly plant doing yellowish, you can increase the pH of the soil by adding any mulch, peat moss, or pine needles around the plant.
What Compost to Use Instead
Mushroom compost has a ton of essential nutrients for your plants. There are other options that won’t lessen some of the acids that plants need in a soil. Consider any of the following:
- Potting soil,
- Worm composting,
- Poultry manure,
- Cow manure,
- Mulch,
- Kitchen compost.
Some Plants Like Mushroom Compost
Some other plants love mushroom compost and like alkaline soil.
Many vegetables can thrive this way as well. Many trees can thrive this way without acidic soil.
Here is a quick snapshot of some of the popular plants mushroom compost will help:
- Goldenrod
- Lavender
- Delphinium
- Easter lilies
- Columbine
- Virginia creeper
- Winter jasmine
- Boston ivy
- Lilac bushes
- Ornamental cherry
Is Compost Made From Mushrooms Safe?
Some folks have questions about the safety of using mushroom compost our gardens and fields.
The story goes that mushroom growers utilizing chemicals in the the growing process.
The concern is that chemicals are or could be in the mushroom compost they farm.
Best practice would be to inquire with the farmers the chemicals they use on the mushroom crops.
Some chemicals could have toxic levels of residue that could contaminate your plant’s health.
Be Careful: If you apply mushroom compost with toxic materials included to your plants, you may harm, or kill it.
Conclusion
Certain plants dislike mushroom compost because of the alkaline nature of the mushroom compost.
Acid-loving plants, particularly the ericaceous family, don’t like mushroom compost.
Mushroom compost can provide a lot of nutrients and helps to hold moisture; however, it neutralizes the acidity the plants require.
You should find a substitute for mushroom compost when working with this plant family.