I have saved this article about Mushroom Compost because it flies in the face of current fertilizing trends. I pass it on just FYI.

Here is a link that might be useful: Mushroom Compost Over Hyped

Thanks for the article Maryl. I use some chemicals in the garden, so that isn't a huge issue for me. I just want to know if it an effective fertiler. Thanks
Nancy

It's an effective soil amendment. The actual fertilizer (NPK) content may be very low. Soil amendment isn't quite the same as a fertilizer.

We have used mushroom compost as a winter mulch for years now. It's so easy to use and when the crowns are unccovered we just spread it out over the garden area. Sure does save a lot of work not having to move soil or other material around. But when I read that article it makes wish I hadn't consumed so many mushrooms. We love them and use them in a lot of different dishes! I would honestly like to think that mushroom producers shouldn't be allowed to use harmful chemicals on a food product. But then who really knows what goes into our bodies now-a-days!

I was reading through older posting and the Mushroom Compost article caught my attention. I have been buying mushroom compost for the past 2-3 years by the pickup loads. I will say, growing roses for the past 15 years, I have never grown better roses than the last two years. I primarily use the compost for soil amendment, It has made my soil light and loamy, just wonderful. I do feed my roses with other organics. I have been very happy with the mushroom compost that I have been purchasing and have to give credit to this compost for giving me much better and healthy roses.

It depends on your soil pH. My brother in Michigan has acidic soil, and he has to put lime into the soil: so alkaline mushroom compost is good for his soil.

I have alkaline soil, pH of 7.7 - mushroom compost at $5 to $6 per bag was a disaster. My rose turned very chlorotic (pale, yellowish leaves). I had to replace the soil. It's good to get your soil tested professionally before any amendments.

Karl recommended EarthCo. at drgoodearth.com for $20 they test for organic matter, phosphorus, potassium, magnesium, calcium, and accurate pH for a cup of soil. The soil-test kits at HomeDepo, Menards, and Lowe's are worthless and gave false pH since they use a very tiny soil sample (a few teaspoons!)

Some mushroom growers add a lot of lime as a fungus control. Some samples of mushroom compost are reported to have a pH over 8. One of our posters (maybe Paula?) reported problems with roses growing in mostly mushroom compost owing to high pH causing nutrient deficiencies. Labels of compost normally do not report pH, so you don't know what you are getting.

For these reasons, I would not buy it. If I were given some free, I would test the pH before putting it in or on rose soil. If the pH were 6.8 or lower, I would use it like any other decayed organic matter.

I reported my soil test on another thread. My soil is composed of purchased (Lowe's) top soil and mushroom compost. I have considered mushroom compost almost natural and a part of my no spray routine.
My test results:
ph 7.5
nitrogen 4 (normal 40)
phosphorus 245 (normal 65)
potassium 338 (normal 250)

We really have had no soil, just sticky clay. I have amended my entire garden with a combination of top soil and mushroom compost.

Mary, I thank you so much for this information.

I would love to know if these processes were used in top soil or other products that we think are natural in our gardens.

Sammy

When you buy mushroom compost by the truckload around here, you're getting plain old cow manure straight from the cow (meaning not even composted). I'm not sure about what's in bagged stuff.

I do use mushroom compost, but not bagged stuff. We have a very large commercial mushroom producer in town and you can get the stuff in bulk for very cheap.

I read the article. It makes some good points but also makes assumptions that are not universally true. He compares shroom compost unfavorably to peat moss and to straw - are you kidding me??? Peat moss and straw have no nutritional content, which is what he disses shroom compost for. Peat moss is harvested unsustainably, through what amounts to strip mining or mountain top removal mining. And peat moss is bad for your soil here in the summer-dry Pacific Coast. It repels water in summer, and makes the soil waterlogged in the rainy winters. Straw? he can't be serious. Straw is a mulch, not a soil amendment.

Shroom compost has the advantage of being thoroughly decomposed organic matter, which is exactly what our soils need. Maybe in other places that's not so critical. Our soils are recently glaciated and have very little organic matter. My garden soil has only the organic matter that I add - when I did a particle analysis on moving in, there was no measurable organic matter.

His point about the pesticides used in mushroom production are good points if valid. (since his comparisons to peat moss and straw are not valid I have to question everything else too.) I've never asked the local company just what, how much, and how often they use pesticides. I'm not trying to be certified organic. But if I were, it would be good to know that mushroom compost may have pesticide residues. Keep in mind that these things do break down over time! especially in a high organic matter environment.

High pH, again, is not a problem in our area since our native soil is very acid. In alkaline areas people don't use things like cow manure due to pH problems, and cow manure tends to be a major ingredient in shroom compost.

Kayli, please note that the author of the article doesn't say that mushroom compost contains all these pesticides. All he says, is that commercial shroom producers are licensed to use them. He does not say that they do use them, or how much, or how often, or whether he's had shroom compost tested for residues, or anything. I do give him points for honesty but it requires a careful parsing of his text as he's really trying to persuade without out and out lying. His conclusions may be valid but he doesn't present data to allow us to draw our own conclusions.

In my area, roses and plants in general love mushroom compost. There's nothing in this article that persuades me not to use it as an amendment to add valuable, thoroughly composted, weed-free organic matter. In other areas, it would depend on the quality of the source and the characteristics of the native soil. I don't use it for winter protection as it is too soggy for our conditions. I've lost roses to canker when I've tried it that way. In colder drier winters it is probably fine.