Easy to grow, daylilies come in a wide range of colors, shapes and sizes. With a long blooming season, daylilies are relatively pest and disease free, drought resistant and tolerant of most soil conditions. Originally from Eurasia, the lemon daylily (yellow) and the tawny daylily (orange) were brought to the New World by colonists and were popular farmyard plantings. The tawny daylily spread to roadsides and became known as the "ditch lily." Despite humble beginnings, modern hybridized daylilies have become a mainstay of hot, summer display gardens.

Not true lilies (which are Lilium in the Liliaceae family), daylily’s genus is Hemerocallis. Hemerocallis comes from Greek words for day and beauty. Most species open at sunrise and wither at sunset, usually replaced by another one on the same scape (stalk) the next day, though some species are night-blooming. A single plant may produce over 100 flowers, extending a plant’s bloom period for several weeks.

The American botanist Dr. Arlow Burdette Stout (1876-1957) was the pioneer breeder of the modern hybrid daylily. He worked from 1911 to 1948 at the New York Botanical Garden. In over 50,000 cross pollination experiments, Dr. Stout produced more than one hundred viable Hemerocallis hybrids, revolutionizing nursery breeding and popular interest in daylilies. In 1950, the American Hemerocallis Society established the Stout Award in his honor, considered the most distinctive award in annual recognition of Hemerocallis hybridization.

Today more than 58,000 cultivars have been registered. Over 12,000 are available commercially, with periods of bloom ranging from very early to late in the growing season. Daylilies may bloom with iris in spring and continue into fall with chrysanthemums.

Most daylilies are deciduous (foliage dies to the ground each winter), although some are semi-evergreen or evergreen in mild climates. Deciduous varieties are commonly referred to as dormant. The arching foliage consists of long, linear leaves that grow one to two feet tall. Leaves are a rich green color. The erect, leafless flower scapes rise from the crown of the plant and extend above the foliage. The scapes of most varieties range in height from eighteen inches to five feet tall. Five to 30 or more flowers are present on each flower stalk. Flowers range from less than two inches across, for miniature varieties, to over 12 inches. Flowers are available in almost every color, except blue and true white. Some varieties have attractive eyes (centers) and throats. Others are polychromes, with blends of related or contrasting colors. Edged flowers occur when the petal or sepal edges vary with lighter or darker colors. Many of these colors and characteristics are the result of extensive hybridization programs.

The root system of daylily plants varies from an almost fibrous type to the common fleshy type. This fleshy root system, in part, differentiates the daylily from true lilies that grow from bulbs.

Growth needs

Daylilies grow best in full sun and tolerate partial shade. Although they are known for their tolerance of poor sites, they perform best in soils that are well drained with abundant organic matter. If fertilized heavily, foliage will be overgrown and flowering will be poor. One application of a complete fertilizer, such as 10-10-10, in early spring should be adequate. Water once a week to a depth of eight to ten inches and more often during prolonged periods of drought. Mulching is beneficial. Winter mulch applied in late fall should be used on newly transplanted daylilies. Once they are established (experienced one winter) daylilies do not need winter protection. Winter mulches should be light and airy. Coarse materials such as straw or leaf mulch work well.

Remove dead foliage and debris from plants in early spring and late fall. Check plants regularly during the growing season to remove damaged or yellowed leaves. Some daylilies produce seedpods after the flowers fade. Unless you want to experiment with seedling plants, faded flowers and flower stalks should be removed before seeds are produced to ensure that all of the plant's stored food reserves go to the roots, so that the plant will make a good flower showing next year.

Propagation

Daylilies can be propagated through division or by hybridizing. Division of large clumps is an easy way to add quantity to the garden. Trading and sharing daylily divisions is a great way to add variety to your collection. Clumps can be divided when they become overcrowded, usually every four to six years, by separating the plant into rooted segments, each with one to two shoots. This division is referred to as a fan. Because the root system is so vigorous, you may need to use a spade or garden fork to get the pieces apart.

Daylilies can be divided in spring as new growth is emerging, or during September. Planting may also be done in the early spring. Avoid dividing blooming plants. Dig a hole large enough to accommodate the roots and plant the crown of each daylily at soil level, but no more than one inch below soil level. Tall cultivars should be spaced 24 to 30 inches apart, with smaller types 18 to 24 inches apart.

Since the mid-1970s, backyard hybridizers and entrepreneurs have been changing how daylilies look and perform. Dozens of American hybridizers are recognized for their distinctive approaches to form, color, plant health and performance. High bud count is commonplace today. Repeat flowering has been bred into many new cultivars, offering more than one cycle of bloom within a growing season. Colorado gardeners who browse nurseries and catalogs for recently bred daylilies will discover thousands of enticing varieties or can make the daylily variety of their own by hybridizing.

The 2006 Stout Medal winner is “Ed Brown” hybridized by Jeff Salter. Current popular cultivars include: Bark at Me, Beautiful Edgings, Bela Lugosi, Bill Norris, El Desperado, Fooled Me, Moonlit Masquerade, Orange Velvet, Peggy Jeffcoat, Point of View, Primal Scream, Red Volunteer, Sabine Baur, Sandy B, and Strawberry Candy. For more daylily information visit the American Hemerocallis Society (AHS) website at www.daylilies.org

The public is invited to attend the Northern Colorado Iris and Daylily Club’s annual AHS sanctioned show at Fort Collins Nursery after 12 noon on Saturday, July 22. Daylily flowers will be on display until 4 PM. You can also see over 300 daylilies in bloom at Houston Gardens, 515 23rd Avenue in Greeley, Colorado.

Attached photographs taken by Dick Christensen.

The authors have received training through Colorado State University Cooperative Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County.

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This page updated:  July 18, 2007