How often do you intend to call by and maintain the garden? I ask because lavenders such as L. dentata are definitely drought-hardy but need regular trimming to stay healthy and not become lanky. The same with the Salvias.

I like the idea of the Echeverias so long as you choose something such as 'hen and chicks' - otherwise other people 'just take a little bit' and the planting disappears.

Gerberas are a possible - especially the single ones.

The Sedums are fine - the 'Autumn Joy' - but poor old Vera might be competing with the inevitable weeds. If the yard has been neglected for so long you'll have a seed bank bigger than your Federal Reserve. I find it is easier to mulch heavily and weed very thoroughly for one to two years, then put in the lower-growing plants. The soil will be better and the competition cleared away.

Be sure to avoid anything with thorns of any size. No one wants to weed around or under them.

One I'd add, purely because I like the scent - Aloysia triphylla - lemon verbena, although it, too, needs regular pruning to be attractive.

And, if the soil allows, Leucadendrons and Proteas are quite drought resistant, too.

How about some trailing lantana it's very drought tolerant. The nursery here has them in pink, white, lavendar, & yellow this year. It should stay evergreen in your zone and bloom almost year round. We trim ours back only about twice a year.

We also live in Oakland. I didn't have any luck with agastache and Autumn Joy sedums. The agastache didn't like our cold wet winters, and the Autumn Joy looked horrible. I think it needs more heat than we get. The flowerheads barely turned pink for two weeks, then started going brown, then went black and the stems yellowed. They all looked awful. I yanked out all but two which are in out of the way corners.

Osteospermums do well and should be on your list.

Don't plant ANYTHING until you have spent sufficient time killing off the Bermudagrass. It took us 3 successive sprayings with Round-up over a period of 8 months, with watering in-between to make sure we got all of it. Bermudagrass is incredibly aggressive and will send underground runners 6' away under concrete to infest surrounding areas. No plant can compete with weeds; in our frost-free zone they must either be pulled or sprayed.

Don't forget to mulch, it will make weeding in the future much easier.

Trailing lantana is more rust-resistant than shrub lantanas, BTW. I have both, and the shrub lantanas look pretty bad from December-March. They'll do well with either exposure.

Hellebores will do well with the eastern exposure.

What is plecanthrus neochilus? Do you mean Plectranthus? I have Plectranthus argentatus but that certainly isn't drought-tolerant.

Helichrysums are very drought resistant and pest-free. Give them plenty of room because they'll take off enthusiastically. But they're easy to cut back since the long stems don't root. Beautiful foliage, particularly the variety "Limelight".

Aucuba, of course, for a eastern exposure. Gives fast verticality, never has any problems, and 'Gold Dust' or similar variegated types are eye-catching.

New Zealand flax (phormiums) will do very well with a western exposure and varieties like "Yellow Wave" or "Dazzler" or "Maori Princess" are colorful and carefree. Keep them dry and avoid overhead watering, BTW.

The trailing verbenas seem to need a lot more sun and warmth than they get from me. But there's a rare shrub verbena, V. lilacina 'De La Mina', which is a 2' tall, 2' wide, bloom powerhouse. Lacy foliage and spikes of little purple flowers -- it has never stopped blooming since I put it in over a year ago with a western exposure.

And of course, the standard Erysimums -- 'Bowles Mauve' and the 'Variegata' are regularly available at the HDepot garden centers. They are short lived but dependable, fast growing, and although they look better with an annual deadheading, they don't really need it. Downside is that the flower spikes are pokey rather than soft, so site it where you're not brushing against it. They will lean towards the sun. 'Bowles' gets 3' tall and around, 'Variegata' is a 1' tall trailer. Both have lavendar blooms year round.

Good luck! Kudos to you for being a concerned property owner, too.

aloe vera or medicine plant , prickly pear cactus (fruit strain ) there is also a Galopagos strain that is taller.
jojoba prized for its oil, will grow in desert conditions.
other possibilities that might work but might not: beach plums (the plums are the size of a nickel and have stones they are a low shrub) , bilboa tree from Africa , eucaliptus from Austrailia, monkey puzzel tree Patagonia ,
peach , almond . the most drought resistant corn is an american Indian strain sold by www.nativeseedsearch.org but i don't remember the strain. read up on deserts around the world and keep us posted on what you find . The most arid desert is in South America Argentina I think . check "xeroscape"

the locust tree ( there are probably commercial strains )and possible the carobe tree can survive in aridc land also the desert chia which can be purcased as seed from www.nativeseedsearch.org in Tucson AZ.
THERE ARE RESEARCH GROUPS such as "desert plant research group " out of some of the universities in the southwest .
you may wish to check "The Encyclopedia of Organizations" in your library for similar groups.

Veter,
I can HIGHLY recommend the Candlestick Bush. I have it planted outside my chain link fence where it doesn't get watered. Here in zone 8a, mine has grown to 5' x 5' in a year. It dies back in winter and surprises you when it comes back so well. It is VERY drought tolerant and a FAST grower. I watered mine in the first year. After that, never.

I have seeds, too. What seeds do you have to trade that are drought tolerant?

Xtal