Clematis?

Sedum?

:)

Monkeygrass if you just want a groundcover. You can go with the spreading kind that will be more uniform and will be contained by the concrete or the mounding traditional kind that looks a little showier when blooming. The stuff will grow anywhere. If you want an edible, maybe Christmas lima beans than can climb the wall.

How much sun does the area get? Do you want ground cover or something bushy? You might consider placing coleous there, they come in many different colors and will grow tall and bush out.

Sorry for the slow response! I'm hoping to grow some sort of edible. It's a north facing wall in zone 10 (Los Angeles). Since the wall forms an "alley" between my house and this wall, I've noticed that much of the day is spent in shade.

How much shade are we talking? I've been growing my pole beans up a trellis on the side of my house. I'm sure they aren't as productive as they'd be in a sunny spot, but it's better than nothing!

coleus! depending on the type you could thread it up through the trellis

japanese forest grass takes shade.

Mint plants do well in shade. Have you considered a passion fruit vine? I've come across conflicting information. Some say it needs at minimum 6 hours of sun, but others say partial shade is fine if grown in a warm/hot climate which would apply to you. You already have a trellis.

Some merigolds would add color and life.

If you like greens, they do well in semi-shady spots. Look up "vegetables that grow in shade" and you'll get a lot of ideas. Your choices are not as limited as you may think. Sweet potatoes would do well in the summer and provide ground cover and greens too.