Characteristics of Daylilies

Foliage and Form

• Daylily foliage varies slightly in color and more dramatically in size. Depending on the cultivar, the always green foliage may have different tints ranging from yellow to blue. The leaves can grow from 6 to more than 36 inches in length, remain slender or grow wide, or have an arching or upright form; but they always grow outward from a central point in the base and have a linear form. The foliage grows quickly to form dense clumps. Also depending on the type, the leaves may die back as winter approaches or remain evergreen or semi-evergreen throughout the year.

The Blooms

• The flowers of the daylily rise above the plant on leafless stalks, called scapes, that generally range from 12 inches to 5 feet tall, although some may grow even larger. As the name suggests, individual flowers only last for a day, but each plant produces successive flowers for three to four weeks, making the blooms more than just a passing thing of beauty. Daylilies, depending on the type, may produce flowers ranging from yellow to red and pink to purple. They may have one solid color or a blend of two or three colors in different arrangements. They may form a trumpet or a circular shape, a more spidery shape, have ruffled petals or take on one of the many other forms of the flower.

Climate and Culture Preferences

• Daylilies grow in U.S. Department of Agriculture plant hardiness zones 3 through 10, depending on the variety. Most flower best in full sun, but the darker-colored varieties, those with deep red and purple blooms, prefer protective shade during the hottest part of the day. Daylilies thrive in well-draining, organically rich soil, with a pH between 6 and 6.5. They can tolerate a wide range of soil types, however, as long as the area does not flood.

Care

• Daylilies require little care once planted, especially if they sit in a good location, and often thrive even when neglected. Once established, they tolerate drought, but appreciate at least 1 inch of water per week during the growing season -- more if you live in a hot, dry region. To keep the appearance of the plant neat, clip off spent flowers, remove the scapes when flowering is completely finished in summer and take out the foliage if it dies down in fall. Daylilies have few pests, but those that can cause some damage include aphids, spider mites, thrips, slugs and snails. Daylily diseases are also rare, but include daylily rust, rot and leaf streak. You can avoid many of these problems by cleaning out dead foliage, dividing dense clumps in the spring to increase air circulation and only watering daylilies in the morning.