I think there's more to it.

I'm not clear over whether this is indoors or outdoors, though it seems like it would be indoors.

If it's outdoors, you probably already have mushrooms or other fungus living in the ground there, especially if it's a very moist spot. Virtually every location in nature is colonized by something. If you want something specific, you might need to find a way to clear what's already there.

Also, different species survive different ways... some form symbiotic relationships with the roots of plants, some consume mostly dead wood, some consume mostly dead leaves/stems, some live more broadly in the soil and consume things like dead roots, some parasitize other fungus, some parasitize plants, etc.

If it's indoors, and you really don't care what you grow, there is a bananna yellow mushroom called Leucocoprinus birnbaumii that grows in all sorts of flower pots in houseplants; it's particularly well-adapted to living indoors and manages to get there unintentionally well enough that practically anyone who discovers a mushroom in a houseplant has that species. It does grow in soil. You might be able to ask around and see if someone you know has accidentally discovered it in their own houseplants and you could grow by setting the mushroom itself in there, or by getting any amount of soil from a pot where it is growing and transferring it to your own. It's interesting because of the bright yellow color.

sorry, while I was writing the first post, I was trying to figure out why I had been thinking the garden was outdoors when your description seems like something that would be indoors... decided to re-write it in light of the fact that it seemed like something in a greenhouse. Then I closed the page and re-read the title.

Yeah, outside you'd be facing a situation where the soil is already surely colonized by existing species.

You could set a fresh log on top of it that is uncolonized by any mushroom species and then you'd get to pick whatever you want - including edible mushrooms you can order online.

Hello Pizzuti,

Sorry for the very late response, i lost track on this thread.

This garden is outdoors but is in a shaded area under a deck and a lattice blocking out alot of light. That makes sense that some spores may not germinate as there are other colonies already in place... but i rarely see any mushrooms and would really like more.. Maybe i should impregnate some logs with spores?

once again thanks for the good info and sorry about not responding right away.