I had this plant when I used to live in so CA. It did really well in full sun, west facing.

Lady Slipper - Euphorbia macrocarpus

https://horticultureunlimited.com/plant-guide/lady-slipper-plant/

Some grasses would do well too, but be careful you don't get the types that are crazy invasive.

Another one we had in full sun was Portulacaria Afra - Elephant Bush. There are several varieties and you want the upright variety, which you don't see as often.

One idea I have is to plant a row of Mexican Bush Sage. However, assuming they need about 4 feet of area, the narrow strip will not be able to fit those as show in the picture below. Any ideas on how to handle this? Or suggestions of another layout? Thanks.

Here is a great resource: www.waterwisegardenplanner.org . I live in SF Bay Area, have done a lot of native planting, can answer other questions, but that site is great.

Watch a few Laura Eubanks vids on youtube. She does all over socal succulent gardens.

most varieties of lavender would fit into your narrower space. You could even do a variety rather than all the same. if you wanted something less gray germander is green, spring flowering and looks good all year. If you did a drip system vs sprinkler with mulch it would save water and look nicely finished.

I want to layer the plants with smaller sized plants (ground cover?) in the front and larger shrubs in the back. Any suggestions on what smaller size plants would go well with lavenders?

Teucreums, cossonii and chamaedrys are great ones that look good all year, are drought tolerant and flower in spring, but the lavender would fill up your narrower section all by themselves.

Ummmm.... lavenders and rosemarys get old and the middle bare in just a few years and will need to be replaced. You might want to find something that will last a lot longer.

I have seen very old rosemarys that looked fine, it depends on a lot of factors. I recommend CA natives ceanothus and buckwheats whenever possible. Manzanitas too if you really want beauty. All these need full sun and are very low water once established.

@CA Kate z9

Thanks for the input. What low-maintenance shrubs would you recommend?

Rosemary is going to be a bush in So Ca! You might want to look at stepables.com for drought resistant ground covers.

There are all sorts of Rosemary. I like the "carpet" ones for a smaller area; but they eventually all get bare and woody in the middle with green on the ends. I don't care for this look, the OP may not care.

Exploring some options like these, along the 65 ft long wall. Ignore the pathways/walkways, instead using landscaping rocks as ground cover where necessary. What do you think?

I am leaning towards ground cover since I am thinking they will be low maintenace while still provide the green look. On my walks in the neighborhood I have noticed that the city owned landscape uses Myoporum and Coyote Bush. Are those good options?

Love both those and they are low care and look good all year!