Not all flowers recognized as bulb plants have true bulbs, according to University of Illinois Extension. Corms, tubers, rhizomes and tuberous roots also produce flowers. True bulbs, however, have all that's needed through a plant's life cycle. Tulips, hyacinths, and daffodils are common examples of bulbs, but there are some unusual bulbs worth considering.
Not all bulbs are spring bloomers. When the tulips and hyacinths have finished, summer-flowering lilies can take center stage in the garden. Michigan lily (Lilium michiganense) is a summer bloomer hardy to winter temperatures as low as minus 30 degrees F. Native to the wet prairies, meadows, and low-lying woods of the central United States, it stands up to 5 feet high and 2 feet wide.
Michigan lily's lower stems have elliptical green leaves. In June and July, each plant bears as many as eight spotted, red-orange flowers. Backward curving petals give the blooms a cap-like appearance. Michigan lily, according to the Missouri Botanical Garden, looks best in groups. It's a good choice for borders, meadows and native plant gardens.
Autumn daffodil (Sternbergia lutea) is an amaryllis-family bulb native to central Asia and the Mediterranean. Hardy to winter temperatures of minus 10 degrees, this delicate plant stands between 3 and 6 inches tall and wide. In September and October, stems with yellow crocus-like flowers rise above its clumps of arching, deep green leaves. The leaves often linger into winter.
Use autumn daffodils in borders, rock gardens or containers. It performs best in full sun and dry to moderately moist, well-drained light soil. Good winter drainage is essential. Plant groups of bulbs 3 to 5 inches deep and 4 to 6 inches apart in mid-summer. Plants in areas with severe winters benefit from protected locations and southern exposure.
In its native South Africa, bush lily (Veltheimia bracteata) blooms from December to March. In the United States, it's hardy to winter temperatures of 20 degrees F and higher. Grow it indoors elswhere. This hyacinth-family plant stands up to 2 feet high and 18 inches wide, with a dense, flowing clump of glossy green basal leaves. When in bloom, its reddish 15-to-24-inch stalks have dense spikes of nodding rose-purple or yellow-green blooms. Disease and pest resistant, bush lily likes filtered sun and peaty, well-drained soil. Plant the bulbs in late summer for winter flowers, according to the Missouri Botanical Garden.