Lilies Lilium

Lilies are herbaceous perennial geophytes in the lily family (Liliaceae). They are found across a wide range of temperate biomes in North America, Europe and Asia, and some species have naturalized elsewhere. The genus name is a classical name for lilies.

Lilies are bulbous geophytes that overwinter well without having to be removed from the ground for storage. The bulbs of the plant have white, purplish or yellow fleshy scales. They prefer a location with full sun to PM sun for the leaves, shade for the roots, and well-drained, fertile soil and mulch to keep the root zone cool. Overly moist soil can cause bulb rot but the soil should not be allowed to dry out completely. Plant bulbs 8" deep in the fall and be rewarded with showy blooms from June to August.  They are often utilized as border or cut flowers, specimen plants, and in mass planting. They can be grown in a container but will be somewhat smaller.  \Taller plants may need to be staked. Dead-head blooms to reduce energy spent on creating seeds and cut back stems after bloom and when they begin to turn yellow.

Lily groups
Horticulturists typically recognize several groups of lily species and their hybrids. It should be noted that botanists recognize somewhat different groups, but the horticultural groups are most applicable here:

• Asiatic Lilies – These lilies are widely available. They are easy to grow, are short in stature (less than 3 feet tall) but have no fragrance. Asiatic hybrids sold as bedding plants or potted plants typically have upward-facing flowers, but other Asiatic hybrids may have outward-facing or pendulous flowers. Their bulbs are typically white.
• Martagon Lilies – These tall lilies bear many, small, downward-facing flowers and whorled leaves. Their bulbs are usually yellow. Martagon hybrids tolerate some shade and are well-suited to woodland gardens, where they can thrive for many years. Martagon hybrids are not suited to hot, humid environments.
• American Lilies – These lilies are derived from North American species such as L. superbum, L. humboldtii, L. michauxii and L. parryii. They like cool, moist soil in dappled shade. They have pendulous flowers that are usually not fragrant (L. michauxii is fragrant). They have loose bulb scales or elongated, sub-rhizomatous bulbs.
• Longiflorum Lilies – These are the classic Easter lilies with long, trumpet-shaped, white flowers. This group includes the species L. longiflorum and L. formosanum. These are commonly grown as potted plants.
• Trumpet and Aurelian Lilies – This group includes the species L. regale and L. henryi, both of which are popular herbaceous perennials for the sunny border. They may have trumpet-shaped flowers or open flowers with recurved tepals. The flowers are outward-facing or pendulous and come in many colors. The species L. sargentiae and L. sulphureum are included in this group. Trumpet lilies have purple-tinged bulbs.
• Oriental Lilies – These are the most spectacular lilies of the garden. They are tall plants (up to 8 feet), with whorled leaves and many, large, outward-facing, fragrant flowers in various colors, often with contrasting spots on their tepals. These lilies are often used as cut flowers. Their bulbs are usually yellow. Hybrids in this group grow well in acidic, humus-rich, moist soil. Use an organic mulch to keep the roots cool. Hybrids in this group are derived from L. auratum, L. speciosum and others.
• Orienpet Hybrids – These lilies are hybrids between Oriental and Trumpet lilies. They come in a variety of colors and are fragrant. Their large flowers are intermediate in shape, and the plants are tall. 

Quick ID Hints:

• Erect, often unbranched plants with sessile leaves
• Flowers appear fused, but tepals are free to base
• Filaments attached at the base of each tepal

Insects, Diseases, and Other Plant Problems: Aphids can vector lily mosaic virus (no cure once infection occurs); botrytis, bulb rot (from wet, poorly drained soils).

VIDEO Created by Elisabeth Meyer for "Edibles, Bulbs, and Houseplants" a plant identification course offered in partnership with Longwood Gardens.