NancyJane makes an important point. Mushroom foraging is a refined skill, and the vast majority of wild mushrooms are unpalatable or poisonous. Glib, I noticed great big oysters growing in a friend's mucky horse paddock on a poplar stump with rotting roots, so I copied the plan only without the fresh manure. I inoculated a 3-inch diameter, 10-inch tall poplar stump cut in winter, let it run for a season, then piled lots of compost around it to simulate paddock conditions. The next summer brought several nice flushes after soaking rains. I have read this will work on cottonwood, too. I have some new poplars ready to cut, so I'll be trying it again. I live in an opening in a poplar forest, so volunteer trees are constantly trying to reclaim the open space. I need a use for these stumps, and hope to fall into a production rhythm with the oysters like we have with the shiitakes.

I would wait, simply until you allow at least one mushroom to become fully mature, as the spawn looks rather like whisps of smoke, released from beneath the fully expanded cap, by the gills below, prior to drying up.. Place a fully grown cap with the mature gills facing downward on a plate, cleaned as well as possible & dried, to collect the 'spore print'. Otherwise, if you were to damage the mycelium network, you may disrupt the growing cycle. Isn't that why they harvest, by cutting them at the base, as opposed to pulling them up & then removing the base, afterward? I think I may have once re-used, a Shiitake inoculated, tree log, ( that required banging it hard, to resemble falling to the ground, in the forest, to begin production.) simply by placing a Portabello cap on top... (I stood the log, upright, in a large saucer, to keep it moisture level; ample) There is an Italian supplier (Bavicchi?) that I used for Pioppino, that was available within the U.S quite inexpensively ( use search terms Italian Seeds + mushroom spawn, or spores) if in case it is the other Italian Seed source, here in the States, if you'd like to try those, with growing instructions...

Please, Deneciepie, forget about eating your mushrooms. We like you on this forum! I think there's a "rule" about this: don't even consider eating a wild mushroom that resembles a Death Angel unless you are an incredibly experienced mushroomer. Death Angels look like white button mushrooms with pinkish gills that turn black or brown with age. My personal belief is that mushrooms are too cheap to experiment with your liver or kidneys, let alone your life. By the way, I hear Death Angels are delicious. Renee

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.