Perhaps the most solid plant for dry and unwatered gardens in the West is Greasewood, but Sarcobatus vermiculatus is very rare for purchase. (Mail-order: Great Basin Natives in UT) It grows in low, salty, dry clay areas of the west. Potentially car-sized, it is ignored most of the time. But alas, in a garden, with a bit of pruning, it will offer rich succulent greenness entirely without water. It ought to be used more where we don't want to water and weed. Stiff, pointed stem-tips would make it an awesome security screen.
All this so I can post a shot of the underappreciated pink inflorescences.