Yard and Garden: Understanding Daylilies

Daylilies can make a beautiful addition to the home garden

June 28, 2024, 11:22 am | Aaron J. Steil

Daylilies are one of the most popular garden perennials. Their easy care and beautiful flowers make them useful in most gardens. Thousands of varieties are available and new varieties are released every year. The scientific name for daylily is Hemerocallis, which means "beautiful for a day" in Greek. The name accurately describes the one-day bloom period of individual flowers. Learn more about growing daylilies in your garden from questions answered by horticulturalists with Iowa State University Extension and Outreach.

What types of daylilies can be grown?

There are over 100,000 registered cultivars of daylily, showing significant diversity. Their flowers, borne above grass-like leaves, range from 2 inches to over 12 inches in diameter on stalks (called scapes) 15 to 60 inches tall. Flowers vary in shape from trumpet to star to triangular and come in every color except true white and blue. Some have attractive eyes and throats, often with fragrance.

Daylily.While individual flowers last only one day, each scape has many blooms, and each plant produces many scapes, allowing for a succession of blooms over three to four weeks. While most bloom early to mid-summer, some cultivars start blooming as early as late May, and others start later but stay in bloom until frost. Reblooming cultivars bloom for 10 weeks or more. Proper variety selection will allow flowering from spring until frost.

Daylilies usually have 22 chromosomes and are referred to as diploid. Tetraploid cultivars have double the number of chromosomes. In most cases, the chromosome number is important only for those interested in plant breeding. However, many tetraploid cultivars have flowers that are larger and more intensely colored than diploid cultivars. Most varieties with ruffled or frilled petals and bold colors are tetraploid.

How do I care for daylilies?

Daylilies are low-maintenance, thriving in full sun or partial shade. Pastel varieties should be placed in partial shade to prevent bloom fading. They tolerate a wide-range of soil conditions but prefer well-drained soil rich in organic matter.  Avoid excessive fertilizer to prevent abundant foliage growth at the expense of flowering. Clean up dead foliage in late fall, and remove damaged or yellow foliage and spent blooms and scapes throughout the season.

How do I propagate daylilies?

Daylilies can be propagated by division or seed. Daylilies are most commonly propagated by division. Divide plants in early spring (as new growth emerges) or late summer. Dig up the entire clump with a spade. Then, carefully pull the clump apart. Often, a sharp knife is necessary to divide large, dense clumps. Each division should have two or three fans of leaves and a good root system. When dividing daylilies in late summer, cut the foliage back to a height of 6 to 8 inches. Replant the divisions as soon as possible, spacing plants at least 2 feet apart. Place the crown (the area where the shoots and roots meet) approximately 1 inch below the soil surface. Water thoroughly. Newly divided plants may take one to two years to bloom well. Daylily.

Daylilies propagated by seed will not be identical to the parent but can result in new or interesting flower colors and forms. For successful germination, seeds require a moist-chilling treatment, or stratification. Bury the seeds in a lightly moistened medium and place them in the refrigerator for six weeks. After stratification, place them at 60-70 °F, and seeds will germinate in three to seven weeks.

Can daylilies be weedy?

Most daylilies in garden centers are clump-forming hybrids that do not spread. Many are also tetraploid and do not produce viable seeds. However, one species, Hemerocallis fulva, also known as ditch lily, orange daylily, or tiger daylily, is an Asian native that spreads readily via rhizomes and can dominate roadsides, woodland edges and field edges, excluding native vegetation. Plants are long-lived and thrive in a wide range of conditions. This makes this species easy to grow and difficult to eradicate. To avoid its aggressive spread, it's best to opt for non-spreading hybrid varieties in your garden.

Are daylilies edible?

In addition to their landscape uses, daylily leaves and flowers are edible. Edible materials should be gathered from only those plants that have not been sprayed with any pesticides. Three-to five-inch-long young foliage can be simmered or stir-fried. Flower buds and blossoms can also be eaten at any stage of growth. The tight buds can be used in salads, boiled, pickled or stir-fried. All stages of bloom, from half-open to day-old, can be eaten deep-fried with a light batter. Petals can be eaten raw right off the plant and have a buttered lettuce flavor. Since daylilies can act as a diuretic, it's best to eat them in moderation.

Shareable photos: 1. Daylily. Hemerocallis 'Baja.' 2. Daylily. Hemerocallis 'Siloam June Bug.'

About the Authors: