How can I tell if my mushroom compost has been sterilized and is this necessary?

[tulsanurse1]

I was reading where a master gardener was saying that if compost has not sit in the sun for at least 3 weeks, one should not use it. Please read this and tell me if its okay to use the compost I just purchased. It's FaFard Mushroom compost. I've heard it's necessary to get a good crop. Thanks

Every gardener should also consider the following 3 issues very carefully before using manure and compost in containers, raised-beds, or other type of vegetable garden, especially as the main or only ingredients in the soil-mix.
As much as 90% to 95% of the composted materials available to the typical family gardener have NOT been sterilized, or even heat-treated in the composting process. However, in order to have clean materials they must have been composted at 140 degrees or more for about 3 weeks, which is the time it takes to thoroughly compost organic materials aerobically, and that's the only sure way to remove diseases, weed seeds, and bugs.


In addition to the great potential for problems with disease, weed seeds and bugs, using manure and compost, even just for fertilizer, leaves you guessing as to what you are giving your plants by way of nutrition. You never see the list of plant nutrients or their percentages on a bag of manure or compost, because no-one KNOWS them.
And the third reason you need to be careful is that using manure and compost can often lead to a salinity problem and burn your plants. For example, applying 2"-3" of manure to the planting area of a soil-bed or container adds 7#-10# of fertilizer salts all at once to the soil in a 30'-long bed or box. That's more salt than the soil should have in an entire growing season! Imagine the effect of applying that manure to the entire garden or worse yet, making it 25-50% of the entire soil mix!


Rather than using manure and/or compost in your container garden you will be wise to use two or more CLEAN ingredients for your soil-mix, including 30 to 35% sand (by volume) mixed with any combination of the following - sawdust, perlite, peat moss, ground-up pine needles, coconut husks, coffee hulls, rice hulls, or vermiculite - depending on cost and availability.
Plants cannot "eat" animal excrement or compost. Both must fully decompose and their organic parts must revert to inorganic minerals before plants can access them. Plants need small, measured and balanced amounts of 13 natural mineral nutrients dissolved in water and absorbed through the root hairs over the entire course of their growing cycle, rather than a large application of salts at one time. I recommend applying only about 7 OUNCES of mineral salts per week to a 30 foot-long bed or box.

[David Marek]

All mushroom compost should have been hot composted or steam pasteurized so non-mushrooms don't grow in it. A 10% volume added to your mix should be plenty (maybe still too much?). As the quote says, the nutrients are not immediately available, microbes need to assist with that process. I only use compost in large containers. I am interested to see what others have to say about adding various kinds of compost to a growing mix.
http://extension.oregonstate.edu/new...toryType=garde