Prized for their feathery foliage and showy blooms, acacia species hail from such warm-weather climes as Central and South America, Australia, Mexico, and the American Southwest. In the South, they are typically shrubs or small trees, most commonly grown in Florida and Texas. They are relatively short lived (20 to 30 years) but grow quickly, suffer from few pests, and tolerate poor and dry soils. Require excellent drainage.
A. baileyana. BAILEY ACACIA (often called mimosa as a cut flower). Evergreen. Zones LS, CS, TS; USDA 8-11. Most widely planted acacia and among the hardiest to cold. Often grown as a multitrunked plant 2030 ft. high, 2040 ft. wide. Feathery, finely cut, blue-gray leaves. Starts blooming when young; profuse, fragrant yellow flowers early in the year. Thornless.
'Purpurea'. PURPLE-LEAF ACACIA. Same as A. baileyana, except for purple new growth.
A. berlandieri. GUAJILLO. Deciduous. Zones CS, TS; USDA 9-11. Southwestern native planted as a shrub, hedge, or small tree. Thornless growth reaches 15 ft. high and wide. Fernlike foliage. Fragrant white flowers, rich in nectar, bloom winter to spring.
A. farnesiana. SWEET ACACIA, HUISACHE. Deciduous. Zones LS, CS, TS; USDA 8-11. To 20 ft. high and 1525 ft. wide, with feathery foliage and thorny branches. Fragrant, deep yellow blossoms are borne nearly year-round. In the Lower South, however, cold winters may reduce bloom; flowers may freeze in a cold snap in any area. Garden centers often sell the more cold-tolerant A. smallii under this name.
A. schaffneri. TWISTED ACACIA. Deciduous. Zones CS, TS; USDA 9-11. To about 18 ft. tall and a bit wider, with curving branches like green tentacles and finely divided leaves hiding short thorns. Perfumed yellow ball-shaped flowers appear in spring.
A. wrightii. WRIGHT ACACIA, UA De GATO. Deciduous. Zones LS, CS, TS; USDA 8-11. Cold-hardy acacia native to Texas; survives winter as far north as DallasFort Worth. Usually grows to 610 ft. tall and wide, occasionally to 20 ft. Pale yellow flowers bloom in spring on 2-in. spikes. Delicate foliage sometimes persists through winter. Thorns on branches have sharp hooks. Does best in dry, well-drained soil. Not well adapted to the Southeast.