I would try some sweet potato vine.....I love the stuff! It does well all through the summer and comes in a bright green (margerite) and purple. Looks great when mixed together!

It however does not flower. Looks great WITH Flowers though if anyone else might have a suggestion.

Ice plant is a good cascading plant, with little red, pink, or yellow flowers.

A real rascal of a plant, but very nice on a wall, is weidelia. It has dark green foliage and pretty, yellow, daisy-like flowers. It can be very aggressive tho.

Janie

Does Carolina Jessamine do well in DFW? It is awesome this year in Houston...and on sale at every nursery I have been to lately. I have never seen it so beautiful here, I guess it is because we actually had a few freezes last winter.

I had purple potato plant that had lovely big purple flowers on it.
Morning glories are easy and will cascade.
I would think most plants that an grow up a trellis can also cascade down a retaining wall.

I have trailng rosemary on my retaining wall. It has had tiny lavendar blooms all winter. I planted it is 1998 and it is still going great,
It won't be as colorful as you want, but it is maintence free.

I second the trailing rosemary and also suggest calylophus, winecup and lantana. Mix it up a little bit and the rosemary should be evergreen for you giving your wall some interest in the winter in addition to the blue flowers in late winter.

I have heard that trailing rosemary is not as winter hardy in DFW as the upright. My upright does well but if it was trailing, it would take a few seasons to cover a wall. Hope someone from DFW will chime in on this.

I'd second the sweet potato vines and morning glories. Both will add lots of color in a full sun spot. I have to replant the sweet potato vines each year but the morning glories self sow really, really, really well.

I hesitated to mention this one, but skullcap looks really neat falling over a rock wall. Trouble is, it doesn't fall far. It molds itself to the shape of the rock, and can tolerate being planted right next to the rock. This gives a "drop" of about a foot.

I'm SW of FT Worth a bit and the times I tried prostrate rosemary it died over the winter.

Thanks everyone! Having read that the trailing rosemary might not make it through the winter here, I think I will go with the purple sweet potato vine. Can anyone tell me how long this will take to fill in and how many plants I need for the 20' wall span? I assume this is a common plant that can be found in a local nursery?

Wait, Kara--while the purple sweet potato vine really would be beautiful (especially if you mix in some of the bright lime green), it doesn't come back at all, does it?

I've ordered a flat of the trailing rosemary for my rocky bank/wall. I've heard that on those few REALLY cold nights we get, I might ought to cover it, and it should survive. We'll see.

Bo, you are so right about the potato vine. I take cuttings each year, but I have never had it come back.

OK, this is good to know. I am actually wanting something that I can plant now and never worry about again. Any ideas what that might be?

How about aubrieta? Does anyone have experience with it in here?
http://www.highcountrygardens.com/catalog/product/24431/
There's also alyssum
http://www.highcountrygardens.com/catalog/product/16328/
and Veronica oltensis
http://www.highcountrygardens.com/catalog/product/97350/

I have ice plant in an old stump (left about 30" high.) I tore off a few hunks from another spot, stuck it that soil filled stump, and now in it's 2nd year, has covered the stump & trails all the way to the ground. Already beginning to bloom those bright beautiful hot pink flowers which shine like patent leather.

Originally I bought a 4" pot of it at Lowe's and have given away at least a dozen starts larger than I had in the beginning & just last week I took several handfuls from underneath thickest part & stuck them in other spots.

Suzi

Sounds perfect for a cascading, ground cover rose. Two hardy ones that come to mind are Sea Foam http://www.antiqueroseemporium.com/rose-1507.html
and Red Cascade http://www.antiqueroses.com/public/antiqueroses/pg_1/rcascade.htm.
Sea Foam is an Earthkind rose (easy, no spray, etc.) and Red Cascade is known for it's hardiness and is said to be in bloom continuously through the season.

Moss Phlox and Homestead Verbena are also good cascading plants for full sun.