Could you post a picture of the area, or the whole back yard, so we can get an idea of how it's situated?

Here's a picture of my flower bed. I'm looking to put new plants in. It shows the citrus trees and the flower bed which is 30 feet long and only 20 inches wide. Hope this helps.

I see you are in zone 10. I'm assuming that is USDA zone 10, in the US, but is it the southeast or southwest - very different environmental conditions. Without that knowledge, I will not recommend specific plants.

For aesthetics:
1. select some plants that will drape down over that wall in places, softening it and visually connecting the flower garden to the lawn. You could use a hardy perennial like creeping for wooly thyme, or a cascading annual.
2. select plants that will not grow too large for the bed
3. select plants in a variety of mounding and upright habits, in varying heights, and position them for an undulating effect.
4. select plants for a succession of bloom throughout the season, keeping bloom color as well as leaf color and texture in mind when arranging for a pleasing effect.

For the butterflies & hummingbirds:
1. Include a variety of plants that will provide blooms throughout the season. Native plants are best. When using perennials, choose them so you have a succession of bloom (as one is finishing, another is starting).
2. Provide fresh, clean water. Butterflies will also appreciate a muddy spot for "puddling" to obtain minerals.
3. Eliminate or reduce use of pesticides.
4. If you want to support certain species of butterflies, know their host and nectaring plant requirements - certain ones need certain plants: monarch/milkweed, pipevine swallowtail/dutchman's pipe, etc.

There are any number of websites that will list plants native to your region. Below is an excellent article on butterfly and hummingbird gardening; this is written for the Northeastern US, but the same principles will apply. Scroll down and click on the link for the plant list. Again, this is for the Northeast, but there may well be some overlap.

Here is a link that might be useful: How to Create a Butterfly & Hummingbird Garden

Thank You so much for your reply. I posted another picture of the full view of the flower bed and the vegetable garden in the background.
I'm located in the Southwest. San Diego California to be specific.
I like the idea of plants that will bloom in succession, but how to go about picking those plants is beyond my knowledge. We never use pesticides on any of the citrus trees or in our vegetable garden. Everything is organic.
I welcome any suggestions for specific plants.
Thanks again for your reply and have a great day.

Since I'm in coastal NJ, the plants I'm familiar with thrive in our hot, humid summers, brief cool springs and autumns, and cold (at times down to the teens) winters ... Not at all like your climate in southern CA! So it's very difficult to advise. You might be interested in the reference sheet at
http://www.njaudubon.org/Portals/10/BackyardHabitat/PDF/RecommendNectarPlants.pdf

- there must be something like it for your region, although many of the plants would probably do very well in your area with irrigation, which I assume you are providing for your citrus and veggie garden anyway.

Even with our cold winters, I have 12 months of bloom in my garden, so I'm sure you can do it in San Diego.

Take a look at the website of the Native Plant Society of California for general guidelines ... THEN ... here is a find: North American Butterfly Association regional plant guides - download the PDF for the region nearest you (the PDFs are free). These guides contain a wealth of information.

Hope this helps, and that someone more familiar with your region weighs in.

Remember, you don't have to do it all at once. Have a plan, get started, see what works, make adjustments as needed.

Here is a link that might be useful: NABA Regional Butterfly Gardening Brochures

20" wide is extremely limiting. Most perennials will exceed that space easily.

I'd look to annuals......San Diego has a very long growing season and many (maybe even most) annuals are very attractive to hummingbirds and butterflies. In your climate, a good many plants sold as annuals will winter over easily - they are really tender perennials that just won't tolerate winter cold in more northern locations. Routine deadheading and perhaps thinning together with some periodic fertilization should keep them blooming for the longest possible period.

And the best thing about annuals is that they are inexpensive so when they spread too much or begin to look ratty, it is no big deal to rip them out and start with something fresh and small.

http://www.evergreennursery.com/cactus-succulents
http://www.california-cactus-succulents.com
http://www.cactuscenter.com/gallery/grand-tour

You live in my favorite gardening area! there are so many gorgeous succulents that flourish in your area, that bloom in vivid colors, attracting hummingbirds all year long! I can only name the few I struggle to maintain in a window, here in northern Wis. I would plant succulents of all shapes, colors and sizes in your long bed.

I live in Zone 10 in Florida and am currently writing a book on hummingbird & butterfly gardening for this area.

Here's some suggestions:

Pentas lanceolata
Salvia species
Agastache species
Asclepias species
Cuphea llavea
Cuphea schumannii
Gaillardia pulchella (annual)
Tulbaghia violacea
Justicia carnea
Coreopsis species

Sorry about the botanical names but you can Google them and figure out what they look like. For a source in California check Kartuz Greenhouses (www.kartuz.com).