Hi
I used to live in St. Bernard before Katrina. I'm in MS now. I do have several suggestions off the top of my head: lantana which comes in yellow, white, orange/red, pinkish. It will freeze down but come back. Daylillies come in many colors. Stella d'Oro is yellow and one of the easiest to grow. Black-eyed susan also called rudbeckia, daisies, coneflowers. All these will come back after winter (perennials). And then there are many annuals which you plant each spring or seed them, they die in winter but might come back if you have a mild winter or if they reseed themselves; cosmos, verbena, melampodium, million bells, calibracha (spelling?). Well there are just so many. Don't forget old garden roses, not the fussy hybrid tea roses, and the knockout roses which are great for full sun. Sunflowers are neat, and come in many sizes not just the really tall ones. Sages, and other herbs love the sun and have neat flowers. They like it rather dry. If you can try to get the book Passalong Plants, Tough Plants for Southern Gardens, Bulletproof Plants for the South - the authors are Felder Rushing for the first and third book I think, and Norman Winter for the second one. You can do a google search of "Louisiana+sun+perennials" or with annuals. You can search for LSU cooperative extension service or LSU master gardeners and you will be onto a world of info. Good luck, you are in a great area to garden all year round.
Laurie

I love Lantana in any form,,,,petunias, daisies, Mums, elephant ears, while not a flower, look great as a background for your flowers. You need some green to mix with the bright flowers to balance out the look. Asters and coreopsis are great too. Gaillardias are another one you might like. They come in beautiful orange and lemon colors. Heliposis also known as summer sun flower are beautiful. LIgularia is so pretty planted with purple elephant ears....I love purple and yellow together...one just seems to make the other prettier.
Salvias are wonderful and trouble free as far as the ones I have planted. thyme,,,the one called Mother of thyme, I like...
If you plant purple heart with the trailing yellow lantana and Use some large rocks or stones and train the lantana over them with the purple heart in front,,,all your friends will copy you. It just looks so good.