I've tried this a few times with no success. Seeing yours make me think I'll give it another go next summer (winter here). I have a perfect sub tropical climate for mushies.Don't throw away mushroom kits when they've finished fruiting; bury them in the ground outside somewhere shaded, cover with some horse shit and then a layer of compost and keep moist.
I've just this morning pulled a 103g Shroom from my garden and there are more coming through!.
They grow wild near here but you have to run the gauntlet of angry farmers, cops, and the odd bull, so I find it easier indoors.