DayLilies (Hemerocallis)

Day Lilies, Daylily, Day Lily

Named for its extra short blooming time, daylilies produce lovely flowers that last for only one day apiece. The Latin name, Hemerocallis, accordingly means “beauty for a day.” Available in a variety of colors, the ever-popular daylilies are many a gardener’s favorite. The foliage is attractive (even after flowers have faded) and the plant requires minimal maintenance. These flowers are great for filling in large empty areas with mass plantings or lining walkways or garden paths.

I. Appearance and Characteristics 

A daylily or day lily is a flowering plant in the genus Hemerocallis , a member of the family Asphodelaceae, subfamily Hemerocallidoideae, native to Asia. Despite the common name, it is not in fact a lily. Gardening enthusiasts and horticulturists have long bred daylily species for their attractive flowers. Thousands of cultivars have been registered by local and international Hemerocallis societies. Daylilies are perennial plants, whose name alludes to its flowers, which typically last about a day.

Hemerocallis are herbaceous clump-forming perennials growing from rhizomes, some produce spreading stolons. They have a fibrous or fibrous-tuberous root system with contractile roots. The tuberous roots are used to store nutrients and water. The arching leaves are produced from the base of the plant (basal) and lack petioles, they are strap-like, long, linear lanceolate leaves and grouped into opposite fans. The crown is the small portion between the leaves and the roots. The large showy flowers are produced on scapes. The slightly irregular shaped flowers are arranged in helicoid cymes, or produced solitarily. The scapes of some species and cultivars produce small leafy proliferations arising from the nodes or in bracts. The proliferations are clones that root when planted.

Typically Hemerocallis flowers have three similar petals and three sepals, collectively called tepals, and each have a midrib. The centermost part of the flower, called the throat, may be a different color than the more distal areas of the tepals. Each flower has six stamens joined to the perianth tube, each with a two-lobed anther. The unequal stamen filaments are curved upward with the linear-oblong anthers dorsifixed. The superior ovary is green, with three chambers and the stigma is 3-lobed or capitate. The fruit is a capsule (often erroneously called a pod since botanical pods are found in Fabaceae). The fruits may have no seeds (sterile), or many relatively large, shiny, black, roundish seeds. The flowers of most species open in early morning and wither during the following night, possibly replaced by another one on the same scape the next day. Some species are night-blooming. The haploid number of chromosomes is eleven.

Eating too many uncooked flowers of some species can cause diarrhea. Hemerocallis species are toxic to cats and ingestion may be fatal. Treatment is usually successful if started before kidney failure has developed.

II. How to Grow and Care

Sunlight

Daylilies love full sun, so make sure yours gets a minimum of six hours each day. In extra hot climates, some afternoon shade will keep yours in good health (although do this knowing it may lower the number of blooms your plant provides). Darker varieties prefer afternoon shade in hot climates to help retain their color.

Temperature and Humidity

This is a tough plant that can stand up to most temperatures and a wide range of humidity levels. It would prefer about one inch of moisture per week, but it can also make its way through some dry periods relatively unscathed.

Watering

Water regularly in the first growing season. Moving forward, only water if the weather is very dry. Mulch helps retain moisture in the soil, plus it protects the plants in colder winter climates.

Soil

Despite thriving in all soil, daylilies would rather being planted in one that’s fertile and loamy. Just make sure the soil is moist: sandy or clay soil may be too dry. Adding compost can help it retain moisture. Also ensure that the site is well draining to prevent root rot.

Fertilizing

Most daylilies do not need fertilizer. Instead, add compost each season to provide added nutrients to the plants and amend the soil.

Planting Instructions

Pruning

Unless you’re looking to propagate them, avoid letting daylilies go to seed. As with many plants, seed production distracts the plant’s energy from flower production. Remove any seed capsules whenever you see them and cut each scape to the ground.

Remove any yellowing leaves throughout the growing season. Doing so will encourage the plant to produce new leaves. If desired, remove spent blooms, too, by gently twisting the wilted bloom between your finger and thumb.

Propagation

Propagating daylilies is done through division.

They should be divided every three or four years in either fall or very early spring. Divide no longer than five years to encourage prolific blooming.

To divide, dig up the plant. Remove excess soil, and place on a tarp or cardboard to minimize mess. Using a sharp knife or spade, Divide into smaller clumps. Make sure each section has a healthy clump of roots, and check that there are no weeds nestled in the roots, and then replant immediately.

How to Grow from Seed

While it’s possible to buy daylily seed packets, if you already have the plants growing in your garden, you can harvest the seeds directly from them. However, most daylilies grown in the garden are hybrids–meaning that the seed-grown plants will not produce true to the parent.

To do so, wait for a seed pod to dry on the stem to the point that is brown and about to burst open. At this point, snip the seed head and remove the seeds. Store them in a dark, cool place in a paper envelope until you are ready to plant.

Before planting, subject the seeds to moist cold stratification for about 30 days. Then, plant them in a deep container such as a 16-ounce cup. If your seeds didn’t germinate during the stratification process, they should sprout in about two to three weeks in the soil. Keep the soil moist and transplant seedlings to the garden in June or July.

Seeds can also be sown directly in the soil in the fall months.

A particularly fun part of growing daylilies from your own seeds is that you can experiment with cross-pollinating the plants and have new varieties crop up in your own garden. To accomplish this, simply use a cotton swab to remove pollen from one plant’s flower and deposit it on the pistil of another plant’s flower. If seed pods form, you’ll have your own new cross-bred daylily to plant.

Pests and Diseases

Common Pests and Plant Diseases

Daylilies are generally pest-free. Even rabbits tend to avoid them, although deer do tend to find the entire plant tasty.

Prevent the occasional slugs and snails from coming their way by picking up leaf litter around the crown of the plant. Check in early spring for any aphids around the first buds and check for spider mites or thrips in hotter weather. If any of these are found, clean with insecticidal soap.

Common Problems 

Daylilies are strong, relatively carefree plants, but sometimes problems can arise.

If your plant’s leaves begin turning yellow, the problem is likely not enough water. If the plants are getting less than an inch a week of water naturally, you will want to supplement so that they get enough.

If the leaves begin turning brown, it is probably leaf scorch, a non-deadly but common daylily condition that can be addressed by tinkering with the plant’s growing conditions. You can also remove all dead leaves, or cut the plant back to the ground after it is done blooming to encourage new growth, if there is still time left in the season.

Overwintering

Daylilies pretty much take care of themselves in the winter. Dormant varieties generally lose all foliage after the first frost. If they don’t, feel free to cut them back to just a few inches above the ground, or you can wait until spring at which time you can pull dead stems easily away from the crown. Adding a layer of straw or leaf mulch before winter temperatures really drop can help the plant withstand excessive freezing and thawing.

III. Uses and Benefits 

Daylilies are an economically important group of plants used medicinally, as food, and as horticultural plants. They have been cultivated in East Asia starting in China for thousands of years. Hemerocallin, a root neurotoxin, has been used as poison and therapeutically as part of traditional oriental medicine. Some flowers of certain species such as Hemerocallis citrina are used in Chinese cuisine. They are sold fresh or dried in Asian markets as gum jum (金针 in Chinese; pinyin: jīn zhēn) or yellow flower vegetables (黃花菜 in Chinese; pinyin: huáng huā cài). These are used in hot and sour soup, daylily soup (金針花湯), Buddha’s delight, and moo shu pork. The tubers and young leaves of H. fulva can be eaten raw or cooked. The flowers are more palatable upon cooking.

Moreover, Daylilies are among the most popular North American garden plants. Registered cultivars of Hemerocallis now exceed 38,000, including more than 13,000 named clones of H. fulva (G. Grosvenor 1999; R. M. Kitchingman 1985; R. W. Munson Jr. 1989; W. B. Zomlefer 1998).

DayLilies (Hemerocallis) Details

Common name Day Lilies, Daylily, Day Lily
Botanical name Hemerocallis
Plant type Bulb
Hardiness zone 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Growth rate Medium
Height 1 ft. 0 in. - 3 ft. 0 in.
Width 1 ft. 0 in. - 3 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition High Organic Matter
Flower color Gold/Yellow
Leaf color Green