sorry....just saw this. here's a good link that lists the salt tolerance of various plants.

But....don't salt your pond. You don't need it. I know it's a common believe that you need to salt your pond, but that is not correct. Koi and goldfish are not salt water species and gain nothing by keeping salt levels in the pond. The use of salt should be reserved for when fish actually NEED it, such as when they are sick or to treat a select few parasites. Keeping salt in the pond all of the time makes it ineffective when it is actually needed for treatment purposes.

Here is a link that might be useful: Bonnie's plant

Blue flag and lousiana Iris will tolerate being under salt water for at least 48 hours. Blue flag grows here in brackish water, which would be too salty for fish.

Carex, willow, cattails, sagittaria and parrot feather all went under salt water for >24 hours and came back.
Tally HO!