What's the scoop on Yellow Flag Irises?

My cousin gave me some Yellow Flag Irises and I'm not sure exactly where they need to be. She has super rich soil and waters everything constantly so I'm not sure what I should do. There also seem to be lots of different varieties and no straight answer on how to take care of them. I know she had them planted next to a pond, but not in it so they aren't the water variety.
Do they need full sun?
Amended soil?
Should I treat them like my bearded irises?
How deep do I plant etc.

These are water iris and need more moisture than bearded and even more than some other beardless. If you have a pond put in a pot and stick it in the pond (shelf is best). If not pot in a pot (BIG) and solid and plant in the ground. These are very evasive and should not be near a natural water way and in many states they are considered a noxious weed.

Except that I am hosting a cultivar of I. Pseudocorus I would not have it one my property with out precautions.
The picture is of I pseudocorus growing in the back wash of the Toutle River which is the river that was destroyed during the Mt St. Helen's erruption. the other noxious weed growing with it is skunk cabbage

http://davesgarden.com/pf/go/666/index.html
here are some positive and negative experiences withthis iris
Anita

Yes definitely keep an eye out if you plant them, and deadhead before they set seeds.

They will grow in regular garden soil, but will not be as tall. Also will not spread as much.

Plant them like Siberian or Japanese.

I do have a couple of them, and have had no problems yet. I also am not near any waterways where they can invade. I grow many of the cultivars, and have had no problems with them, although I am in a Northern state, and it will be different where you live.

I would check with your Dept of Ag to see if they are problamatic there, and would not grow them if they are.

I have some planted in several different places in my yard. They are rarely watered unless by rainfall. I guess that keeps them in check, because I haven't had any problems with them in the many years I have had them planted. They do multiply rapidly, but in my experience they stay in clumps.

The pods float so you don't want to spread them by growing them on a waterway.. Ones in my garden are well behaved.
inanda

They are invasive here; I'm in a similar zone to you.

Mine are planted in a pot without a hole, sort of a mini pond. I keep the water level at or just below the soil level and they are doing just fine. They are invasive - Here is info from Univ of FL http://plants.ifas.ufl.edu/seagrant/iripse2.html

I don't know if I have the hybrids that aren't supposed to be as invasive or not but I put them in regular soil (not near water) and I hope they will be ok there. I haven't seen any in the ponds or waterways around town but will keep deadheading and watch out. If they start causing trouble in my yard in the compost heap they'll go... the last thing I want to do is release the outbreak monkey :-)

Iris never go into a compost pile. Always put them in the garbage. You don't want any iris diseases in your compost.

I treat them like ordinary TBs or any other bearded iris. After the first month (when you do have to keep them damp so they will root well), I just water them like anything else in my garden. They are invasiver if near waterways. Otherwise don't worry about them being invasive.

inanda