Mushroom compost is fairly alkaline and usually has a lot of salt content (I've read)...the absolute worst thing to do to an azalea.

Azaleas (decidious rhododendrons) and their evergreen cousins, are not the best plant for an amateur. They require proper siting, proper soil chemistry, proper watering, etc.

If you want to be successful with them, it will require lots of reading and effort, they're not plant and leave alone plants in most areas.

If you have clay soil, the very last thing you want to do is amend individual planting holes with better soil, composts, etc. All that will do is create an area of very moist soil trapped by the slower draining clay........in other words, a bucket of overly wet, slow to drain soil. It is the kiss of death for all but the most water-loving bog plants.

And you absolutely need to know your soil's acidity before planting these acid-loving plants.......otherwise you are just throwing your money away.

Gardengal, I've always wondered this. If its not good to amend clay soil how can you deal with the clay soil? Clay soil is water retentive in general so if you don't amend it thats bad too isn't it?

Does your clay soil drain? Mine does without any amending whatsoever.

I haven't amended a single planting bed or individual planting hole in my entire yard. We added several azaleas this spring, as a matter of fact. A tree we planted ten years ago in heavy clay has grown so large that we now have lots of shade in the front yard.

I feel that "transplant shock" is a myth in regards to most plants. My satsuki azaleas didn't even stop blooming when we planted them into this Alabama clay. No irrigation, just hand watering as needed.

It looks like the plants in the shade are doing better so it must be a lack of water problem. Azaleas appreciate a little shade and good drainage.

Have you checked to see if the sprinkler head is doing it's job? It could be plugged, aimed the wrong way, or not programmed to turn on often enough.

Were the amendments mixed in with the native soil or did you plant the azaleas in just the amendments?