Compost, compost, and more compost! Any organic matter that will break down and feed the soil and organisms in it will help- the compost is already fairly well broken down. You'll just have to wait and see on the plants, but if you end up having to replace some goners, probably plants native to the area would be best adapted to survive future salt baths. I've heard that daylilies are often the only plants that survive long-term salt water exposure, because of their long tap roots. Of course they're also gorgeous and super-easy, so I love them. Good luck!

Saltwater is most toxic to plants because it dehydrates them, causing what looks like burns. Have you had any good snow/rain storms since the storm? (I'm in the Mountain west, we've been super dry this year, but New England is so much wetter I'm hoping your azaleas will have had at least a few good, clean soakings since then.) If your soil has a salt crust on the top, obviously removing as much of that from above root structures before composting would be very helpful.

I did a google search for plants that survived Katrina, found this nice story about a rose bush that survived after almost 2 weeks under salt water in Plaquemines Parish. So maybe two hours under water won't be as detrimental to your rose bush as you fear.

Also, remembering my time in Mississippi post-Katrina, I seem to remember some bulbs coming up on empty lots (the houses had washed away), but their bloom time was delayed. I don't remember irises, but having never been to Mississippi pre-Katrina, I have no idea if there were tons of tubers before the storm.

Good luck! I grew up in Massachusetts, the plant I miss most in Colorado is the azalea. Broke my heart to learn it wouldn't grow here.

the ground is still so saturated, and the ground water is still so high that low lying parts of the garden pool up, and I'm not sure that it's just rainwater.

One of the local nurseries has reopened.. I think I'll see what they have in the way of mulch..

I thought some were pretty cold hardy.

it's that we have too much alkaline in our soil, and the sun is unrelenting. And remember that Denver is a mountain-desert region. Azaleas also need more humidity than what naturally occurs here.

The spread of violets that got a salt water bath died almost immediately. I am worried about the red cedar that is there, but so far it seems okay.