This is very hard becoz weeds and plants will grow there probably anyway, becoz of birds, other animals, and water and wind bringing seeds.
However, I thought of canna lillies, lantana (the old fashioned reddish-orange ones get big and come back, daylillies (the old fashioned tawny kind, sort of orange color), crinums - a kind of lilly, again an old fashioned passalong plant, irises becoz they like water, tall grasses or sedges, find out which ones like water.
Good luck with your project.

How about monkey grass. You can do through it about once a year to weed but once it fills in, very little else will grow. Lantana was another good suggestion. Miss Huff is a good orange variety. Also, the pink and cream one is very good. Very little grows under them and they are very pretty.

Louisiana iris, lobelia cardinalis, lobelia siphilitica, cannas, pitcher plants, joe pie weed,lady fern, stokesia, boltonia. And many more!

I have used asiatic jasmine in areas where mowing is difficult (on steep banks, etc). It is fast growing and can get out of control but overall it has worked fine.

Spider Lilies are beautiful. They grow wild by the millions just one hour from New Orleans.

Wild blue iris's here in St. Bernard Parish. I will have some in my garden this year. Likes it wet.

Asian Jasmine will grow very easily from cuttings.

Spike Rush is one of my favorites and, it is also a wild and free plant. Will grow in or near water.

Horsetail Rush, a plant left over from the days of the dinosaurs, can get a little invasive but, is pretty and unusual. Loves ditchbanks.

There are even some free pink Crinums growing wild near here.

Just a couple of inexpensive ideas. Email me if you want some specific locations to harvest these free plants.

Ray

Thyme looks lovely anywhere and mine grows all year long here on the Coast 8b. Right now it is flowering and has beautiful little flowers. It will reseed and the thyme keeps getting thicker. A wonderful bonus is you can use it for cooking. I just threw a lot of old hay (must be old) around it in the beginning and as the hay broke down it fertilized the soil. It will spread out and make a wonderful ground cover. It is close to the ground and very neat looking. You don't have to weed it even in the beginning if you use the hay around it. However if you don't like the look of the hay (I do) you can use other mulch that you do like better. Eventually it will cover the area.

Liriope-green or varigated, alone (alternating the two) alone or among other plants--being suggested.
Liriope and Monkey grass are neat, need no mowing.

Good luck, would like to get an update on what you decided.

GB