Come to think of it... Who needs trees or bushes or even flowers when you have a climate where succulents thrive year-round?
This Millbrae, CA (about 20 miles south of San Francisco) front yard fulfills all garden needs with (almost) entirely succulents.
Designer Daniel Nolan, of Flora Grubb Gardens, uses tree aloe in lieu of a more predictable choice. Strappy Aloe plicatilis gives the grey-green shrub effect (how much better is it than juniper??), Cotyledon orbiculata offers bright red flowers, and 'Angelina' sedum makes a great groundcover. The fluffy yellow shrub in the background isn't a succulent, but it's a very low-water 'Pisa' leucadendron.
Icing on the cake? This puppy needs next to no water. Plus the whole thing looks like a Dr. Seuss wonderland.