There was a very nice article on "water iris" published by Horticulture magazine sometime back that is a good resource. It is important to take the subject of 'water iris' with a grain of salt - most iris do not tolerate standing water year round but some are happy in very moist or boggy conditions on a seasonal basis.

Here is a link that might be useful: water iris

Lizey,

Your former 19th century dump can be beautiful with your back-breaking work.

But need to know what zone you are to be able to recommend plants.

Louisianas are mentioned in the excellent article linked above. Again don't know if they will survive winter in your zone.

Thanks for the article tip. I'm in Maine. The hope I have for VERY wet feet is having seen them growing IN water on the edges of islands here in mid coast Maine. It seems amazing that they are on the edge of SALT water, with feet in fresh. And thanks for the confidence that this nightmare spot could ever be friable. The big enemy is deep toxic sections of ancient burnt coal, grey and horrid. I was going to dig it out but it's too pervasive, so no food growing there. BUT it is one of the only spots to garden on this piece of property so I'll continue to plow forward making spots for certain flower seeds in spring AND iris! Will keep you posted as to whether they make it or not, once I dig some from an island or buy some.

I believe Japanese irises can grow in marshy conditions. I don't know if they overwinter in Maine, though. You may want to check out the websites for the Japanese and Louisiana Iris societies.

Here is a link that might be useful: Japanese Iris Society