Taiji
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What about mushroom compost

A few weeks ago I bought a couple of bags of mushroom compost for the first time. I thought, wow, I'm really getting a good bang for my buck here because the bag was pretty heavy, but inexpensive. Then, I noticed one of the ingredients was gypsum, and having bought gypsum before, knew a small bag of it is really heavy.

I looked online about mushroom compost and found a couple of people don't like to use it because they say, after all the organic matter decomposes, all you are left with is the gypsum. After awhile, you would get a giant buildup of gypsum in the soil. Do you folks think that would be a problem? Should we limit our use of mushroom compost for that reason, or does the gypsum eventually break down too?

Mr green
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Re: What about mushroom compost

I would not worry about the small amount. But im personally looking into growing mushrooms my self and "plugs" seems a good thing for me for a variety of mushrooms to innoculate logs. You can find other solutions than gypsum if you like
Gypsom will break down as well, but things that are less natural and if steadilly appleid tend to stay/accumilate in the soil, even so with many "natural" amendmendts".
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Taiji
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Re: What about mushroom compost

I guess was thinking that due to the heavy weight of the compost bag, quite a high percentage of it might be the gypsum which is heavy. I'm not worried about its use for a couple of times, but if I wanted to start using it as a soil amendment year after year, maybe there would end up being too much gypsum in my garden soil. I don't know. Thanks for your thoughts. :)

Actually, I reread my first post and I don't think I explained myself very well. I'm not sure if we're on the same page. I bought mushroom compost which is spent mushroom growing medium, to use as an amendment to my existing garden soil for when I plant things. I'm not trying to grow mushrooms. The mushroom compost has some percentage of gypsum in it, I'm not sure how much.

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Allyn
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Re: What about mushroom compost

I use quite a bit of mushroom compost, but I also use other composts, too. Even on the back of the bag of mushroom compost, it recommends using a combination of compost materials so you get a variety of beneficial microbes. I've never been concerned with the amount of gypsum in the compost as it is a widely used soil amendment and adds calcium and sulfur to the soil. Anything you add too much of can be a problem, but if you switch up your composts, I don't see it being a problem.

Taiji
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Re: What about mushroom compost

That sounds good, thx. I have been mixing some other composts in with the mushroom stuff most times when I use it.

AnnaIkona
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Re: What about mushroom compost

To provent the gypsum, I just get lots of chicken droppings (half composted) from local farmers (for free) instead of the bagged stuff from the store.
Zone 8b, Canada

imafan26
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Re: What about mushroom compost

I used to like mushroom compost and it works well if you have an acidic soil because it is alkaline. I switched to a blended compost later on. It is still alkaline, but I think a blended compost is more balanced that one from a single source.

It is often very akaline because it contains poultry manure and can contain used hay from stables. It also contains a lot of salts that would not be good for salt sensitive plants.

I found that if I used too much mushroom compost, it held too much water and I would see the fungal filaments in the soil.
Happy gardening in Hawaii. Gardens are where people grow.

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applestar
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Re: What about mushroom compost

I was putting away some bags and noticed one was mushroom compost so I took a picture of the back FYI:
image.jpeg
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Taiji
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Re: What about mushroom compost

Thanks for the info. I recently tested my soil ph and the little gauge read about 7.25. I wasn't surprised since I'm in such an arid climate. I assume those gauges are accurate for ph at least. I do like the water holding aspect of the compost though, the more of that the better around here. This is what the back of my bag shows for comparison:
mush.JPG

imafan26
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Re: What about mushroom compost

I would still add sulfur to correct the pH. Gypsum does not affect pH much unless you have saline sodic soils, but the chicken manure will tick it up half a point and it does contain salts as well.
Happy gardening in Hawaii. Gardens are where people grow.

Taiji
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Re: What about mushroom compost

Thx. How would you add the sulfur? Pure sulfur, ammonium sulfate, or some other source?

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