this is why i would suggest you use a media... instead of a soil ... or a compost ... and also why i would sterilize my media before using ... see link i dont know the name.. its irrelevant .. you are getting them.. because you are using 'unfinished' compost in your gizmos ... mushrooms are one of natures decomposters.. and when you use an unsterilized media.. that has vegetative material.. and mushroom spores.. when you add water.. you get shrooms .. see link for a very easy way to sterilize your stuff when i did seeds... i started things in flats.. one line per plant ... and transplanted into 6 oz solo cups at the first true leaf stage ... i sterilized the cups also ... and wrote name on them with sharpies.. and reused them every season after a wash in 10% bleach ... i sliced the bottom edge in 3 place on each cup for drainage ... below is a pic of a couple hundred under common fluorescent shop lights ... oops... forgot.. this is the name that plant forum... some of them might get upset i am actually talking about plants [or argue that a mushroom is not a plant, rather a fungus.. lol] ... i hang in the annual and perennial forums should you wish to further this discussion .... might find some other peeps there who can help ... good luck ken Here is a link that might be useful: link

Yes, it is actually quit pretty. Well, these mushroooms appear every year at the same time, at the same location. So there is something underneat that this is growing on, I am guessing an old tree stump, as the previous owners did clear some trees in my yard. In all my research I 'think' it is a Jack-o-Lantern mushroom. Seems to fit all the descriptions. Being a Jack-o-Lantern makes it poisonous !!!

They are shitake ONLY if you SEEDED shitake spores in your garden. I wouldn't advise eating any mushroom that just appears in your garden. So many poisonous 'shrooms look like the good kind. A REALLY good book is the Audubon Society Field Guide to North American Mushrooms. It's got loads of full color photos. (I wouldn't want to guess what your variety is, but DONT EAT IT.)

Is it a puffball? see this website-- http://www.mushroomexpert.com/puffballs.html