Hemerocallis Description and Cultural Information
Daylilies have been in cultivation for thousands of years and there are thousands of different hybrids in varying colors, sizes, heights, and bloom times, along with reblooming, everblooming, and extended blooming characteristics, fragrant flowers, or double flowers. There are diploids, tetraploids, and many awards from the "Stout Silver Medal" to "Junior Citation".
Choosing which daylilies to grow is a difficult task, but it still tends to come down to color and personal preference. Reds and purples are often popular. The dwarfs often make up for their size in total number of blooms. Double flowering varieties can also be quite eyecatching and reblooming varieties are always welcome in the garden.
Here are some of the basics to consider when shopping for daylilies:
Bloom time: By combining different varieties with different bloom times you can extend the daylily season.
Flower size: Flowers may be single or double, bi-color, or spidery. Sizes range anywhere from about 1.5" wide up to 8" wide.
Plant height: There is a wide range of heights in daylilies. Most heights refer to the height of the bloom stalk and range anywhere from about 10" up to 48" or even higher.
Reblooming: These plants usually repeat bloom so that they bloom in more than one bloom period, such as early and mid or mid and late.
Everblooming: These plants bloom through all three bloom periods.
Extended blooming: These blooms last longer than most, and are often open up to 16 hours.
Fragrant: Some daylilies have very fragrant blooms, others somewhat fragrant, and others no fragrance at all.
Nocturnal: These daylilies open late in the day or evening and remain open until the next morning or early afternoon.
Dormant: These plants go completely dormant in the winter, and some go dormant shortly after blooming.
Semi-evergreen: These plants may hold their foliage better and be evergreen in warmer zones.
Evergreen: These plants tend to hold their foliage all year, but plants may take longer to get established in northern gardens (plant these earlier in the season in the north).
Tetraploid: These plants have double the chromosomes and tend to be stronger growers with thicker and more abundant flowers.
How to Grow: Daylilies are tough and adaptable plants that are very easy to grow. Plant them in average to rich, well-drained soil in full sun to part shade. The species will bloom just as well in part shade, but hybrids perform best in more sun. When planting, daylilies prefer a dry start, especially while they are dormant or cut back. Once they are actively growing they can be watered occasionally and benefit from a light application of fertilizer each spring. After a few years they can spread to form dense clumps and can be divided and replanted at almost any time during the growing season. As part of regular maintenance, remove any brown or yellowing leaves from the base in late summer to keep the clump looking nice. Some varieties are semi-evergreen in warm climates and remain tidy year round. Lift, divide, and replant into amended soil if flowering has faltered from year to year or in order to propagate.
Some common pests and problems on daylilies include rust and other fungus problems such as leaf streak and spots, which can be treated with fungicides and by completely removing and destroying the foliage in the fall. Mites have also become a problem on daylily foliage, requiring repeated insecticide applications to break the life cycle, and aphids and thrips are known to be problematic, again requiring insecticides. Check fungicide and insecticide labels to choose the best product.
Landscape Uses: Although each flower lasts one day, the blooms follow each other day after day for weeks. You can extend the bloom season by combining early, mid, and late blooming varieties. They make excellent mass plantings where other plants may have trouble growing such as steep hills or in below average soil, or they even work well with trees and shrubs. Use groups of daylilies to "corral" spreading plants such as obedient plant (Physostegia) or bee balm (Monarda). Plant early blooming varieties with early summer perennials such as Iris and poppies, and plant midseason and late bloomers with summer perennials such as coneflowers (Echinacea, Rudbeckia), lilies (Lilium), asters, and ornamental grasses.