Lilies (Lilum spp.) Are striking perennial plants with trumpet-shaped blossoms. These relatives of the trillium plant come from lights and develop mainly in temperate woodland habitats. In cool climates, lilies prefer full sunlight, but hot weather may harm them, especially if the weather is dry. Not all of the lily-like plants at your local nursery are really members of the Lilium family, even though they may create similar flowers. True lilies can be divided into several basic horticultural classes.
Oriental and Asiatic Hybrids
Oriental and Asiatic hybrid lilies, descended from indigenous Asian lily species, create big, bright flowers that make up due to their lack of powerful scent. While both hybrid types may look similar, they have very different hardiness demands. Relatively hardy Asiatic hybrids bloom early in the season at U.S. Department of Agriculture plant hardiness zones 3 through 10, though some species may survive as far north as USDA zone 1. Oriental hybrids, more hardy than indigenous Oriental lilies, are still tender to both heat and frost. They do best in USDA zones 6 to 9.
Martagon lilies and their hybrids develop readily and bloom early. Gardeners can identify them by their distinctive whirled leaves and turned-back petals. Because of this flower shape, martagons are also referred to as turkscap lilies. These flowers tend to be fairly small but numerous. According to Valley K Greenhouses, a martagon plant may produce up to 50 flowers per stem. Martagons grow well in shady places but need mulching in warm climates. Turkscap lilies can endure in USDA zones 2 through 10, but need some winter chilling.
American hybrid lilies are derived from species indigenous to North America. These lilies bloom in early to midsummer and like cool soil with dappled shade. Since they’re derived from North American species, these lilies are generally hardy even in very cold temperatures and will grow in USDA zones 4 to 8.
Aurelian and Trumpet Hybrid Lilies
Also called AA lilies, these plants create very hardy bulbs and huge flowers with powerful cologne. Aurelian hybrids bloom comparatively late and needs to be planted deeply. This amazingly hardy hybrid may withstand a wide climate range, however, the huge flower heads occasionally break off in stormy weather. Stake plants to decrease the risk of this problem. AA hybrids can endure in USDA zones 5 through 10.
Crossing lilies from various horticultural types results in interdivisional hybrids.These include the LA and OT hybrids, which have increased flower size and coloration along with improved hardiness and the capability to tolerate a wider variety of conditions. OT hybrids are also known as Orienpets and bloom late in the year. LA hybrids are acceptable for USDA zones 4 through 10, while the fragile OT hybrids boom in USDA zones 5 through 9.
Wild Lily Species
Often called “species” lilies, these plants are wild specimens that develop naturally all around the globe. Originally believed inferior to more colorful and durable hybrids, these lilies have grown in popularity during the early 21st century. Their more natural look and growth habits produce them perfect for gardeners who prefer natives and people who want a challenge. Most North American species lilies can withstand winter temperatures well below freezing, but Asian species lilies could have trouble growing in regions colder than USDA zone 6 or 5.