Members of the genus Hemerocallis, daylilies are low-maintenance plants that work well in many different landscape settings. Daylilies are hardy perennials that grow vigorously and bloom faithfully, even with little care or pampering. However, to get the most out of your daylilies, be aware of a few growing conditions that influence bloom production.
Originally native to Asia, daylilies were introduced to North America by European settlers more than 100 years ago. Modern hybridization has created thousands of varieties in a multitude of colors, shapes and sizes. Flowers are carried on stalks that arise from a mound of long, slender green leaves. Stalks range in height from 1 foot to more than 4 feet. Although individual blooms last only one day, each stalk produces multiple buds that bloom over a period of weeks. Daylilies typically bloom between June and late August, depending on the cultivar. Although yellow and orange daylilies are most familiar, flower colors include shades of red, peach, white, lavender or deep purple.
Daylilies prefer sunny locations. They bloom best when they receive at least six hours of sun daily. Partial shade is acceptable in humid, southern climates to keep flowers from wilting in the hot afternoon sun. However, too much shade decreases blooms. If your daylilies are not blooming well, check to see if nearby trees or shrubs need to be trimmed back to allow more light.
Although daylilies tolerate poor soil conditions, they thrive in rich, well-drained loamy soil. When planting daylilies, loosen the soil at least 1 foot deep and work in organic material such as compost or peat moss. To encourage vigorous flowering, fertilize plants with a low-nitrogen fertilizer in early spring and again before bloom time, but be careful not to over-fertilize. According to Perdue University, too much nitrogen reduces bloom production and causes foliage to yellow.
Daylilies can withstand neglect and survive drought conditions, but too little water decreases blooms. Ideally, daylilies should receive about 1 inch of water weekly. During bloom time, the plants may need to be watered more frequently to keep them moist. However, daylilies do not grow well in soggy, wet soil. Mulching around the base of the plants helps the soil stay cool and moist during hot, dry weather. Be careful not to plant daylilies too close to tree roots that will compete for water and fertilizer.
The best time to plant daylilies is in late summer or early fall, to give plants time to establish roots before winter. Daylilies can be planted in spring but may not bloom well the first year. Daylilies tend to spread vigorously but produce few blooms if they become overcrowded. Dividing daylilies at least every three to five years stimulates new growth and promotes flowering. Daylilies divided in the spring will not bloom as well in the summer, so wait until blooming ceases to dig up and divide them.