Native to Mexico; longtime favorite in Southern gardens. Noted for powerful, heady fragrance. Blooms in late summer or fall, with glistening white, tubular, 2-in.-long flowers loosely arranged in spikelike clusters on stems to 3 ft. tall. Long, narrow, grasslike basal leaves. Double-flowered selection 'The Pearl' is most widely available; it's a good garden plant but not as long lasting a cut flower as the single type. 'Mexican Single' is a more dependable bloomer in the Lower, Coastal, and Tropical South. 'Marginata' has white-edged leaves.
P. howardii, another Mexican native, grows in alkaline soil and has red-and-green blooms that attract hummingbirds. Hybrids between it and other species are good choices for the Southwest. They include P. x bundrantii 'Opal Eyes', which has 2-ft.-high spikes of violet flowers in midsummer.
To bloom year after year, tuberoses require a warm season of at least four months before flowering. Start indoors, or plant outside after soil is warm. Set rhizomes 2 in. deep, 46 in. apart. If soil or water is alkaline, apply acid fertilizer when growth begins. Where winter temperatures remain above 20F, rhizomes may stay in ground all year; divide clumps about every four years. Even in those mild areas, however, most gardeners dig and store them over winter. Dig plants in fall after leaves have yellowed; cut off dead foliage. Allow rhizomes to dry for two weeks, then store them in a cool (4050F), dry place. Tuberoses can also be grown in pots and moved to a protected area during cold weather.