Daylilies are rugged, adaptable, vigorous perennials that endure in a garden for many years with little or no care. Daylilies adapt to a wide range of soil and light conditions. They establish quickly, grow vigorously, and survive winters with little or no injury.
Figure 1. Daylilies typically grow one to four feet in height and produce numerous flower buds that are showy over a long period.
Daylilies belong to the genus Hemerocallis and are not true lilies. This Greek word is made up of two parts: hemera meaning day and kallos meaning beauty. The name is appropriate, since each flower lasts only one day. Some of the newer varieties have flowers that open in the evening and remain open until the evening of the following day. Many of these night blooming plants are delightfully fragrant.
Figure 2. Daylilies are hardy perennials that grow well in Minnesota.
Each daylily plant produces an abundance of flower buds that open over a long period of time. There are many varieties, a wide range of flower colors, and the flowers continue during the heat of the summer.
Daylilies are useful in the perennial flower border, planted in large masses, or as a ground cover on slopes, where they form a dense mat in just a few years.
Site and soil
Daylilies grow best in full sun. They will tolerate light shade, but flower best with a minimum of six hours of direct sun. Light shade during the hottest part of the day keeps the flowers fresh. Daylilies should not be planted near trees and shrubs that are likely to compete for moisture and nutrients.
Although daylilies are adaptable to most soils, they do best in a slightly acidic, moist soil that is high in organic matter and well drained.
Figure 3. A properly planted daylily.
Daylilies can be planted almost any time the soil can be worked. Till the soil deeply before planting. Work in well-rotted manure or compost to increase organic matter. Apply fertilizer based on a soil test. Contact your local Extension office for soil test information. Dig a hole large enough for the roots without bending or crowding them.
The best time to transplant or divide plants is early spring or immediately after flowering. Plants divided in the spring may not bloom the same summer. Divisions should have two to three stems or fans of leaves with all roots attached. Make divisions by digging the entire plant and gently pulling the fans apart. Cut the foliage back, leaving only five or six inches. Place the plant in the soil so the crown (the portion where the stem and root meets) is one inch below the ground line. Water thoroughly after planting. A winter mulch of straw or shredded leaves helps ensure against winter injury for unestablished plants.
Daylilies are vigorous growers and can be divided every three to four years.
In early spring, before growth starts, remove the dead foliage from the previous year’s growth and any weeds. A summer mulch helps eliminate or ease the unpleasant task of weeding. Perennial grasses can be difficult to eradicate if they become established within the clumps.
Although daylilies tolerate drought, they perform best in moist, but well-drained soils. One inch of water weekly is ideal, more frequent watering may be necessary on sandy soils.
Remove seed pods after bloom to prevent seed production. Plants producing seed are likely to have fewer flowers the following year.
Insect control measures usually are not necessary. Aphids and thrips sometimes feed on the flower buds. These pests can be controlled with insecticidal soaps or a repeated strong spray of water.
Annual fertilization may be helpful in producing more flowers. A spring application of manure or compost is beneficial each year.
More than 35,000 daylilies have been named, officially registered, and marketed. Many newly developed plants are introduced annually. Because of their scarcity, some of these new varieties sell for $100 or more, but there are many beautiful, modern cultivars available at reasonable prices. Specialty nurseries often carry thousands of different cultivars. The great majority of new cultivars are developed in southern regions of the United States. Minnesota’s short growing season requires cultivars that are adapted to grow quickly and still survive the long, cold winter.
Daylilies were traditionally plants that stopped growing and became dormant throughout the winter, but today there are semi-evergreen and evergreen cultivars. The first evergreen types were not hardy in the north, but with new introductions there are evergreen and semi-evergreen cultivars that are hardy and will grow and bloom well in Minnesota.
Another new characteristic is the ability to rebloom, or to bear more than one blooming scape per fan of leaves. To date, these reblooming cultivars are not successful in Minnesota due to the short growing season. Another guide to flower number is the bud count per scape or flowering stem. Stella de Oro is a cultivar known for numerous buds or flowers per scape.
Established daylily clumps often produce 200–400 flowers in a season. Bloom time extends from early to late summer. Each plant blooms for 30–40 days. With the large number of cultivars available, it is possible to have continuous bloom throughout the summer.
Daylily flowers come in many colors, shades, and color combinations. Some are very full and round, others have wide petals with ruffled edges and borders. Others, called spiders, are spidery in shape; doubles have double the number of petals and sepals. Many are nocturnal and very fragrant and other cultivars have branched flower scapes.
Daylilies are regional performers which means they grow well only in certain parts of the country, usually over three hardiness zones. For this reason, you should purchase daylilies from a local nursery, a nursery within the state, or a nursery in a neighboring state. If possible, visit a private or public garden such as the Minnesota Landscape Arboretum or a nursery that features daylilies to see which varieties grow in this area and select the ones you like.
The following daylilies are just a few of those that do well in Minnesota, but there are many new cultivars that are equally good.
|Apricot or peach-colored
||Addie Branch Smith
Chicago Picotee Queen
Siloam Bo Peep
Siloam Virginia Henson
Stella de Oro
|Lavender to purple
|Prairie Blue Eyes
||Barbara Mitchell, sev*
Chicago Candy Cane
|Fairy Tale Pink, sev*
Lullaby Baby, sev*
|Siloam Double Classic
Wind Frills, ev**
|White and near white
|Joan Senior, ev**
May, May, sev*
Brocaded Gown, sev*
So Sweet, ev**
|sev* = semi-evergreen; ev** = evergreen
Special thanks to Norman Baker, owner of Northstar Nurseries, and Julius Wadekamper for their assistance in compiling this fact sheet and cultivar list.