There are many mushroom growers in PA. For example, Kennett Square, home to Longwood Gardens, is sometimes referred to as Mushroom Capital of the World. A small mushroom growing company is located about 20 min from my house. After they grow mushrooms for a certain time, they pile the used soil outside, pasteurize it with hot steam, let it age, and then they sell it. Some of the mushroom growers give their mushroom compost for free, but they are about 1- 1,5 hours away.
triple b,
Probably, Hortico was not exactly clear with their statement. It is not recommended to plant seedlings in pure mushroom compost, but mixing it with soil is fine. Unpasteurized mushroom soil may contain some insects and seeds, hot and not completely aged mushroom soil is not good for the tender roots of very young plants. But aged mushroom compost is ... well compost. Here is a link to the site of The American Mushroom Institute http://www.americanmushroom.org/compost.htm
kandm,
There are many mushroom growers in PA. For example, Kennett Square, home to Longwood Gardens, is sometimes referred to as Mushroom Capital of the World. A small mushroom growing company is located about 20 min from my house. After they grow mushrooms for a certain time, they pile the used soil outside, pasteurize it with hot steam, let it age, and then they sell it. Some of the mushroom growers give their mushroom compost for free, but they are about 1- 1,5 hours away.
triple b,
Probably, Hortico was not exactly clear with their statement.
It is not recommended to plant seedlings in pure mushroom compost, but mixing it with soil is fine. Unpasteurized mushroom soil may contain some insects and seeds, hot and not completely aged mushroom soil is not good for the tender roots of very young plants. But aged mushroom compost is ... well compost.
Here is a link to the site of The American Mushroom Institute http://www.americanmushroom.org/compost.htm