Where does the mushroom soil come from that was delivered to our church garden in Philadelphia?
has it been aged and safe to add to garden soil now?
Answer
Questioning whether it is safe to add mushroom soil to your church garden is a valid concern, since it may contain mushroom spores that will result in mushroom growth throughout the garden. It is sold commercially when composted, but is risky when not treated. You need to track down the source of the mushroom soil and make appropriate inquries. I am uncertain on what role PHS may have in the acquisition and delivery of the mushroom soil -- was PHS involved?