Daylilies are from the genus, Hemerocallis, and should not be confused with Lilies which come from the genus Lilium. The following are the distinguishing characteristics between the two plants:

Daylilies are very easy to grow in the home landscape. This probably accounts for the fact that there are over 60,000 named cultivars of Hemerocallis and more being added every year.

In China, daylilies are often used as a food. The flowers are steamed and carefully dried or they may be eaten fresh.

Most daylilies are herbaceous perennials that die back to the ground every fall. However, there are a number of types that are evergreen and, in milder climates, keep their foliage year around. Although most daylilies have a bloom period of 3 to 5 weeks, there are cultivars called "repeaters" which will continue to bloom throughout the summer. Often, they have a larger flush of bloom in the early season and the have smaller number of flowers the rest of the summer. The cultivar 'Stella de Oro' is an example.

Other characteristics that have been developed by breeders include creating some cultivars that bloom early in the season and others extend the bloom season into the fall. There are bloom scape heights from one foot up to 4 feet. Some cultivars have branching scapes with many more buds that usual. Flower substance (petal thickness) varies widely from tissue thin to rubber thick. Flower forms have expanded also with some being described as flat, round, triangular, recurved, tubular, cup shaped, bell shaped, trumpets, orchid like, spiders and others.

Daylilies come in a very wide variety of colors and color combinations. However, there is still no pure white or pure blue daylily. Some advertized as white (off white, near white or tinted white) actually have remnants of pink or other colors in them.

One "drawback" to daylilies is that the blooms open with the sun in the morning and begin to fade by late afternoon. For people who work a 9 to 5 schedule, it is difficult to see the blooms at their peak except on weekends. Well, the breeders are hard at work and are coming up with new cultivars that continue to bloom through the first night and  into the evening of a second day before fading.

Daylilies are very adaptable to a wide array of growing conditions. Generally, they will do best in a light, loamy soil with good drainage in full sun conditions. However, they will grow in poorer soils and will often tolerate some shade although the flower production may decline a bit.

As with most perennials, daylilies are best planted in either the spring or the fall when temperatures are moderate and rains more regular. They are, however, very tough plants and will usually survive any type of mistreatment. I have left daylilies on top of the ground over the winter, placed them in soil in the spring and they have gone about their business as usual.

Many clumps of daylilies survive with no care whatsoever. There are many neglected plantings that seem to keep on flowering. However, for optimum flowering and aesthetics, daylilies may benefit from light fertilization as new growth begins. Also, they should be deadheaded by cutting off the flower stalk after all of the flowers on it have opened and faded. Unless you are hybridizing them, there is no reason to leave the seed heads on the plants. Seed production diverts energy that could be used to build a stronger crown for next year's growth.

As a landscape plant, daylilies have very few, if any, serious insect or disease problems. Thrips may sometimes cause distorted blooms. Occasionally, leaf fungal diseases may cause spots and browning between the veins of the leaves.

Daylilies are very easy to hybridize by seed. That is one reason why there are so many thousands of cultivars around today. Hobbyists and professionals can take the pollen from one plant, put onto the pistil of another and discover new cultivars in the resulting seedlings.

Some hybridizers have employed plant chemicals such as gibberellic acid or colchicines to encourage the formation of mutations in the seedlings. This has resulted in some of the unusual flower forms and colors in recent decades.

Collect the seed in the fall after the seed pods have dried and turned brown. They may be planted immediately in trays indoors under fluorescent lights. Unlike some other perennial plant seeds, they do not need any special treatments such as scarification or stratification. It usually takes 2 or 3 years of growth before the new plants will flower.
 

Daylily cells normally contain 22 chromosomes. Hybridizers have used the compound colchicine obtained from the plant, Colchicum, and available at pharmacies, to apply to daylily flowers during the hybridizing process. This has resulted in the interruption of the cell division process which produces plants with 44 chromosomes in their cells. Such plants are called tetraploids.

Generally, tetrapoloid plants have thicker petals which may feel rubbery to the touch. They often have a slower growth rate. Many of the newer cultivars available today display tetraploid characteristics.

Note: We have provided some general information and observations on this topic aimed at the home gardener. Before you take any serious action in your landscape, check with your state's land grant university's Cooperative Extension Service for the most current, appropriate, localized recommendations.