How to Grow Daylilies

Blooming yellow daylilies (Hemerocallis lilioasphodelus)

 Marina Bagrova / Getty Images

Daylilies (Hemerocallis spp.) are popular for many reasons. These are easy-to-grow perennials ideal for borders and edging, tolerant of drought and flooding, unaffected by high temperatures, and able to grow in most soils and light. Let this be a guide to the most prolific part of your garden for years to come.

Cultivated in a variety of cool and warm colors, these flowers will mix well with any palette. The daylily is a wise choice for novice gardeners who often receive them as gifts from more experienced gardeners. Blooms come reliably in spring to late summer. While perhaps the most commonly known variety is the yellow Stella D'oro, daylilies come in shades of red, orange, purple and pink ranging from a simple "self" patterns (one color with potentially different colored stamens or throat) to more eclectic polychrome patterns (blooms of three or more colors).

Watch the resilient grass mounds give birth to strong flower scapes from which dozens or more flowers will bloom, each for 24 to 36 hours (hence the name "daylily"). Throughout summer, more scapes and likewise more flowers, grow continuously from the center of the mound.

Botanical Name Hemerocallis spp.
Common Names Daylily
Plant Type Herbaceous perennial
Mature Size Eight inches to five feet tall, two to four feet wide
Sun Exposure Full sun (tolerates part shade / light woodland)
Soil Type Deep fertile medium loamy soil (tolerates light sandy or heavy clay) 
Soil pH 6.0-6.5
Bloom Time Spring to late summer 
Flower Color Red, orange, yellow, purple, pink
Hardiness Zones 3, 4, 5, 6, 7, 8, 9, 10
Native Area Asia and Central Europe

How to Grow Daylilies

Daylily clumps can grow anywhere from eight inches to five feet tall. As they will reach a span between two to four feet wide, space bare roots about three feet apart (or for a more dramatic show in the early years, space about 18 inches apart). Plant roots either in early spring or in early fall one month or more before a hard frost.

Measure the diameter of two feet and loosen this area of soil. Dig a hole one foot deep, the size of the root. Put the crown on the mound's center, angling the bulbous roots outwards and a bit downwards. Add soil evenly and tamp to get rid of any air pockets. When the hole is two-thirds full, water generously. Fill the rest of the hole so that the crown is about an inch below the soil surface. Water again.

Light

This perennial thrives in full sun. Ensure that it receives six or more hours of sun each day. In very hot climates, provide some afternoon shade, knowing that the plant will likely produce fewer flowers.

Soil

Daylilies adapt to a wide range of soils from light sand to heavy clay. Still, they prefer deep fertile loamy soil. If your soil is sandy, that means it will likely dry out easily. Add some compost to encourage moderate moisture retention. If your soil has a lot of clay, mix in some compost, peat or leaf mold, all of which provide nutrients and acids for the daylily's preferred slightly acidic soil pH.

Water

Water regularly in the first growing season. Moving forward, only water if the weather is very dry. A light layer of straw mulch is recommended over winter, but do not cover the crown of the plant.

Fertilizer

Apply an extended-release fertilizer to re-blooming daylilies such as Flower Power varieties and others listed below. Doing this in spring will encourage the plants to repeat their flowering cycle throughout summer and perhaps fall.

Toxicity

In a report on the variety Hemerocallis altissima, Plants For A Future cites: "large quantities of the leaves are said to be hallucinogenic [and] blanching the leaves removes this hallucinatory component."

Pruning

Avoid letting daylilies go to seed. Like in 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. (Note that hybrid daylilies will not grow effectively from seed.)

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

Divison

Divide daylilies every three or four years in either fall or very early spring. Take a pair of garden forks, back to back, into their roots until they separate naturally (no need to be overly gentle, they are very resilient). Divide into smaller clumps, check that there are no weeds nestled in the roots, and then replant.

Pests to Consider

Daylilies are generally pest-free. Even rabbits tend to avoid them. 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.

Some Varieties

  • 'Stella D'Oro' is a re-blooming daylily. Its flowers are of a rich golden yellow. They put on quite a show from early to midsummer and re-bloom later in the season.
  • "Purple D'Oro' is another re-blooming variety. It has lavender-purple flowers that bloom in summer and re-bloom in the fall.
  • 'Crimson Pirate' comes in red accented by golden yellow and a gentler sunny yellow throat. Petals are narrow and elongated.
  • ‘Autumn Red’ is hardy in Zones 2 through 9. It has large bright red flowers, yellow eyes, and striped petals.
  • Citron Lily (H. citrina) grows three feet tall. Its sweetly lemon-scented flowers bloom at night.
  • Lemon Lily (H. lilioasphodelus, H. flava) is pictured above. Scapes reach three feet tall, while very fragrant lemon-yellow flowers bloom early from May to June.