There's a good reason why most Southerners see these flashy perennials only at the florist's: They're difficult to grow in regions with hot, rainy, humid summers and heavy clay soil. They may put on a good show for a while, but they seldom last for more than a year or two. A. psittacina and a few new hybrids are exceptions.
A. aurea (A. aurantiaca). PERUVIAN LILY. Deciduous species to 34 ft. tall, with many leafy, flowering stems topped by yellow, orange, or orange-red blooms sprinkled with dark stripes and flecks. 'Orange King' offers outstanding cut flowers, large, long-lasting, dark-spotted, bright orange blossoms reminiscent of tiger lilies.
A. hybrids. The fanciest alstroemerias, often used for cut flowers, are hybrids. The deciduous Dr. Salter's hybrids feature beautiful flowers in red, orange, peach, shrimp, salmon, and near-white; all are flecked and striped with deeper colors. They produce leafy shoots 25 ft. tall in late winter and early spring. As these shoots begin to turn brown, the flowering stems arise, with blooms appearing in early to midsummer. If allowed to set seed, plants will self-sow. They go dormant after blooming. Sow seeds in the garden in fall, winter, or early spring.
Heat-tolerant hybrids (Zones US, MS, LS; USDA 6-8) include 'Freedom,' with peachy red blossoms adorned with yellowish white blotches and carmine specks; grows 2 ft. tall and forms clumps to about 1 ft. wide. 'Sweet Laura' is mildly fragrant, sporting golden flowers with orange petal tips and cinnamon flecks. Grows 2 ft. tall; spreads slowly by underground stems. 'Casablanca' graduated from the cut flower trade to Southern gardens with 3-ft-tall, white summer blooms that are pink on the outside and freckled inside. 'Mauve Majesty' (rose with yellow throat) and 'Tangerine Tango' (golden throat with petals tipped in orange) both grow to a manageable 2 ft. And for small gardens and containers in the Lower South, 'Princess Mathilde' offers coral blooms on 10-in. stems.
A. psittacina. PARROT LILY. A passalong favorite in the South. Evergreen in mildest areas; elsewhere, mounds of dark green leaves emerge from the ground in winter. Flowering stalks, separate from the foliage, sprout in summer and rise to 23 ft. Odd-looking red-and-green flowers are marked with purple blotches. Prefers growing in bright, all-day shade; spreads steadily and can be invasive in good soil. 'Variegata' has striking white-edged leaves.