Drought-resistant flowering shrubs are worthy landscape additions, but the term "drought-resistant" does not mean the plant does best in drought conditions, only that it will tolerate periods of low rainfall or supplemental irrigation. Healthy shrubs, grown in nutrient-rich, moisture-retentive soil tolerate drought better than a shrub growing in adverse conditions. Watering plants deeply once a week during the first summer encourages deep root growth. Transplanting shrubs in the fall is recommended over springtime planting because it allows the roots to establish before the heat of summer sets in.
Gardenias (Gardenia augusta), densely foliated, evergreen shrubs have 4-inch, dark green leaves and produce fragrant, 3-inch, waxy, white flowers in spring and summer. Gardenia plant habit and size varies by cultivar, but may reach 8 feet tall. The cultivarRadicans is a low-growing, spreading gardenia, less than 2 feet tall. Cold hardy to USDA zone 8, gardenias prefer full sun to partial shade locations and fertile, well-drained, acidic soils.
Heavenly bamboo (Nandina domestica), also known as sacred bamboo, is not a true bamboo. It is a clump-forming, deciduous, upright shrub commonly seen 5 to 6 feet tall. Its stems are cane-like with 2-foot compound leaves clustered near the tips. Heavenly bamboo flowers, moderately showy, consist of 1-foot panicles of small, white blooms in late spring. Hardy to USDA zone 7, grow heavenly bamboo in full sun to partial shade in nutrient-rich, organic soils.
Crepemyrtles (Lagerstroemia indica), deciduous shrubs or small trees, reach to 40 feet tall, but dwarf cultivars are commercially available. Cultivar Dazzle Me Pink, reaches just 5 feet high. Crepemyrtles have smooth, showy brown stems with flower colors varying by cultivar, including white, pink, red or purple clusters blooming from spring through much of the summer. Crepemyrtles, hardy to USDA zone 7, prefer full sun and various well-drained soils.
Oleander (Nerium oleander) is an upright, evergreen shrub with many branches often originating from its base. Oleander shrubs reach up to 20 feet tall, with 6- to 12-foot spread. Simple, lance-like, 10-inch leaves are smooth and leathery, dark-green with lighter green undersides. Oleander produces 2-inch, funnel-shaped flowers in single and double forms in red, pink, yellow or white. All parts of Oleander are highly toxic. Hardy in USDA zones 8b to 11, Oleander prefers full sun for best flowering or partial shade on various soil types. Oleander is tolerant of drought, wind and salt.