Maryl:
Here is a general guide that should help you out.
http://zydecoirises.com/Cultur...
Basically LA's are planted the opposite of most bearded iris. They like lots of organic matter, manure and acidic soil. You bury the rhizomes with a couple of inches of soil, cover the bed with mulch. Water often, especially when it is hot. Fertilize at least 3 times a year.
One thing to remember, that I don't think is covered in the link above, is that LA's go dormant right after bloom and new growth starts in early fall. So if the foliage turns brown in the summer or is looking ratty and you want to cut it back, do so in the summer. Once new growth starts in the fall it continues over the winter so don't cut them back in the winter. (This growth cycle doesn't apply the same to northern growers).
As long as they have sun, water and food they are easy growers. Good luck!
