Xill, You should be able to grow many things they grow in Palm Springs and Rancho Mirage. One I am particularly enamoured with is leucophyllum. It THRIVES on heat and will flower all summer with available water. There are several types and a few hybrids. It's a slow grower, but if it gets leggy, you can slash it to the ground and it regrows. If you drive around the Palm Springs/Rancho Mirage area you will see them looking like silk plants! Behind the Mimi's Cafe on HWY 111 (I think it is) they've used it as a hedge in their parking lot. They keep the two types they grow there tightly sheared with regular (don't know the frequency, but it can't be that heavy) and every time I've seen them over the years, they are tight, densely foliated to the ground and paved with flowers. Unpruned, they get open and airy. I grow them here on my hill in Encino and love them. They can get large, so you might want to plant them higher on the slope so they can achieve the privacy you want before you begin shaping and shearing them to be the density you want. There are several foliage and flower colors so you can mix and match to give yourself the texture and colors you want. Plant them as specimen or densely to form a tight hedge (as has been done in town in Rancho Mirage). Absolutely gorgeous shrub which stretches like an old cat in that kind of heat! And, they're native to the desert south west and Mexico so you know they'll work! I have never seen any pest or disease problems with them. Just give them decent drainage, though with careful watering, I've planted them in less than decent drainage and had them thrive in the San Fernando and Santa Clarita Valleys. Municipalities and HOAs are using them for xeriscaping common areas.

Also take a look at Dwarf Myrtle, myrtis communis compacta. It is a weed and can be hacked mercilessly, exploding from thick, old wood, requiring minimal water once established, dense foliage, lovely spring flowers with small, dark blue berries afterward. The foliage scent is lovely and is actually used as a rinse for dark colored hair. You can leave them alone of prune them tightly for extremely dense coverage. They say it grows to three feet, but the fifty year old plants out back are easily five feet by five feet. Here, it gets very infrequent water and full, all day sun. Not that my sun can compare to YOURS, but nothing, not even the gophers and rabbits, has been able to irritate it and it smells SO good! It makes a pretty contrast to the leucophyllum and both should be pretty with your bougainvilleas.

To add other colors, in case they are desired, plant as many Salvia greggii types as you can find. All hot time color, extremely water thrifty and they LOVE heat! Hummingbirds love the leucophyllum and slavia. They come in a variety of color and are another plant you can shear severely and have explode again when it gets hot. I don't know if you have any rabbit or gopher issues, but they leave this one alone, period! Hope they help! Kim

Here is a link that might be useful: Leucophyllum