Best perennial pond plants for zone 7?

[sissy]

Here water iris get out of hand and can eat up a liner if not careful .I pulled one out of a pond that I took out and thought I would use my truck to pull it out but as I did I started to pull the liner with it .I had to stop and take the fish out first and everything else and I ended up ruining part of the liner because of the iris .

 

[HARO]

The tall Yellow Flag Iris (pseudoacorus) will probably be banned here before long. It is currently considered a noxious weed, or something to that effect.
John

 

[sissy]

even the iris's i had in my gardens choked out other plants I had growing near them .I took out big chunks of tubers and moved them to areas where I get wash outs from heavy rains .Yellow ,purple ,black and different shades of blue ones had to be moved

 

[j.w]

The Yellow Flag is a pain here. I am trying to get rid of it all around my pond. I have to lift the heavy rocks around the pond edge to get the big tubers out and it is an ordeal. I got most but still have a few left.Those tubers get so large they lift the rocks and shove them into the pond. Maybe this Summer I'll take out the rest. No more Iris in between rocks ever again!

 

[adavisus]

The fast growing, fast spreading very large rhisome of yellow flag is well suited to stabilising the banks of big rivers where big floods are expected, this is how it is used in Europe along the banks of rivers where you want to protect property from powerful river erosion

Other more ornamental iris choices grow something like 10-20 times smaller, take for example sibirica or ensata varieties, which grow dense and slow, those might take 10 years to fill out a bucket size pot, compared to yellow flag, which can fill several lakes in the same time scale

On a 6" wide pot, its taken 10 years for this ensata to fill it with some 30 or so stems