Forgot to mention, full unrelenting hot sun.

What is the maximum hight you think would work there?

Comphrena, rudbeckia, echinacia, texas trailing phlox to trail over the sides. IF no kids running around, try a member of the cactus family for accent.
Just a few ideas.
weldon

maxiumum a foot to a foot and a half. Thanks for the responses!
amber

Will the bulbs that you planted last year be coming back up again? Do you plan to pull them out?

You could plant Liriope or Lily Turf, over them which would allow them to come up through. In a bed like that, maybe you could have spring, summer and fall bulbs planted along with the evergreen Liriope or Lily Turf. If you go this route, understand it will be very difficult to ever get the Liriope out of the bed should you change your mind about it. I am not sure if the bulbs will continue to come back year after year or if the Liriope will eventually smoother them out. Perhaps someone else knows the answer to that.
There is also a dwarf mondo grass. But I've read/heard that the dwarf in full sun eventually isn't dwarf any longer.

Another thought:

You could plant any of the shrubs (listed below) and allow the bulbs to be between them. Space them so there is plenty of area for the bulbs between.

The only exceptions are the Blue Star Juniper, Juniper 'Blue Chip', Juniper 'Blue Rug', which will eventually spread and cover the whole bed. (it takes a long time though, its pretty slow growing)

google these and see if there is anything you like:

Blue Star juniper

Juniper 'Blue Chip'

Juniper 'Blue Rug'

Arborvitae 'Rheingold

Arborvitae 'Mr. Bowling Ball'

Boxwood Winter Gem

Variegated Monkey Grass (Lilyturf)

There are also many sedums that you could use in that area.

Please let us know what you decide and show us some pictures over in the Gallery section. I would love to see the area you're talking about.

Here is a link that might be useful: RECOMMENDED LANDSCAPE PLANT MATERIALS FOR NORTH CENTRAL TEXAS

You don't indicate if your bazillion bulbs were tulips or daffs that have to be replanted every year, but you might try some native bulbs that return year after year and increase - like oxblood lilies and red spider lilies which bloom in fall, byzantine glads which bloom in spring, gayfeather (liatris) spring or fall depending on variety, some species tulips. I wouldn't do the whole planting in bulbs, but I would put a few around among the shrubs you decide on to get a little color every now and then.
I have a retaining wall with a bed at the top, and tho I use several different native and well adapted plants of varying heights, my best low shrub is Blue Pacific Juniper which grows fairly fast. You could also consider a couple or so nice sized boulders to give some added interest.