I have been in my house for 2 years. There were already irises planted in the yard - for how long I do not know. My first Spring I got foliage but now bloom. Then I was told they may be too deep, so I dusted some dirt off of the "bulbs" or whatever they're called. And then mulched over them.

This Spring I got probably 4-6 blooms (kind of a standard maroonish purple on the outside with a yellowish gold on the inside), but they didn't last any time - much shorter than the irises in surrounding yards. They were watered adequately. They do have a Crepe Myrtle near them that ended up shading them a little bit by the time the bloom was out.

At one point I walked out and found a huge mushroom bloom (the patch was probably 8-12 inches around and the mushrooms themselves were about that same height)in the middle of the fans. Could this have been the problem?

What can I do to extend the bloom?