Xeriscaping, says Purdue University, is a complex concept using regional plants appropriately in water-saving landscape design. Effective xeriscaping groups plants according to their water needs, with the thirstiest ones closest to a home and more drought-tolerant ones further away. California gardeners can plan their xeriscapes around a wide range of attractive water-saving shrubs.
Ceanothus "Concha"--or California lilac--is a large, evergreen shrub standing up to 7 feet high and 8 feet wide. Under the right conditions, with no summer water, ceanothus "Concha" will live between 15 and 25 years. A rapidly growing shrub, it has glossy green leaves and eye-catching clusters of deep blue, fragrant 1-inch flowers in the spring. The shrubs can be pruned for use as hedges, or to prevent hillside erosion.
Plant ceanothus "Concha" in a sunny to partly shady spot with pH-neutral, well-drained soil. Fall planting will give it the benefit of California's winter rains. First-year plants may need need summer watering but established ones do not. Watering them may cause root rot. Mature plants provide shelter for birds.
Another evergreen shrub, blue hibiscus (Alyogyne huegelii) can grow up to 8 feet high and 6 feet wide. It blooms in a range of colors from white and pink to deep purple. While most blue hibiscus plants flower in spring and fall, in ideal situations they may also bloom continuously through the summer. Arching branches and large trumpet-shaped blooms make this plant very showy. Smaller shrubs are effective in containers.
Plant blue hibiscus in sun to part shade with protection from browsing deer. Good drainage is essential. The shrubs tolerate sand, loam or clay. With adequate mulch, they need very little summer water. Light pruning during the blooming season or heavy pruning afterwards will keep the foliage dense. Blue hibiscus' major drawback, says the UC Davis Agriculture and Natural Resource Center, is its susceptibility to aphids and scale.
A 6-by 4-foot evergreen shrub, bush anemone (Carpenteria californica) grows wild by the hillside streams of central California's Fresno County. While this dense compact plant peaks with its spring-to-summer bloom, its dark green glossy leaves make an effective background for other flowering plants during the rest of the year. The mildly fragrant, large white flowers have cheery yellow stamens.
Not as drought-resistant as some California shrubs, bush anemone require additional water when the annual rainfall is less than 20 inches. Plant it in sun--full sun may brown its leaves--to part shade and well-drained loam or clay. Watch its new leaves for aphids and spray them off with water. Shape the shrub with post-bloom pruning.