How can I get rid of all these Mushrooms?
 

I've got mushrooms growing everywhere in my mulch beds. Big ones. Little ones. Flat ones. Tall ones. Part of the problem is all the rain we've had this past spring. Also, some parts of my property have poor drainage or are heavily shaded. Does anyone know how to prevent them from growing? Grass and weed killer seems to have no effect, but I think it may have caused them to mutate into larger versions!

Isn't a mushroom more of a fungus than a weed? I would go to the garden center and find something that kills fungus. Mushrooms grow from spores just like mildew so I would suspect that this would help.

The cheap way would be to mix up some clorox diluted with water in a sprayer or large spray bottle and soak'em down.

Pick um and eat um...Musrooms need decaying matter(Mulch)and moisture, hey you built a mushroom garden! Seriously, mushrooms need an acid soil to do well, if you add lime(sweetens the soil) to your mulch beds you should get rid of most of the mushrooms...Lawns like sweet soil as well, but most shrubs do not.

be VERY VERY careful about any mushrooms you want to consume. Many varieties are super poisonous and can make you very sick.

If they are edible though, eat em :)

That could also explain why we've got so many shrooms; pine needles everywhere from the huge Japanese Black Pines I've got growing along side my property. I'm sure my soil is very acidic. I may try your lime suggestion. Thanks!

Fungicide...
 

I second the lime recommendation. But also, you can find fungicide at the hardware store in the fertilizer section.

I don't recomend eating them unless you are a mycologist or know one that can help you identify them. There are many specie of mushrooms that look just like a harmless specie but are quite poisonous. Not worth killing your liver.

If you want to grow edible mushrooms you can order spores from reputable companies that specialize in these sorts of things and grow them.

Before just adding lime...check the ph to make sure it needs lime.