Gardening Articles: Flowers :: Perennials
by Jack Ruttle
Gardeners can't get enough of daylilies, and it's easy to understand why. Other flowers may be as beautiful, but no other plants are as rugged, widely adapted, or versatile. Daylilies are gorgeous and they are survivors, perfect plants for both the connoisseur and the weekend warrior. Originally from Asia, daylilies have adapted to our challenging and varied climates with all the vigor of our best native plants. They grow in all United States regions, but thrive in USDA Hardiness Zones 4 through 9.
A good daylily variety will bloom continuously for 3 to 4 weeks. By choosing varieties carefully, you can have daylilies flowering for the entire perennial season, 3 months in the North to 10 months in the South.
It's an astonishing performance, but daylilies can do even more. They grow thickly enough to choke out most weeds. They excel at holding the soil on steep slopes and other erosion-prone spots. They bask in the heat of our summers, withstand intense sunlight, and survive drought better than most garden flowers.
That's why we see the old-fashioned Hemerocallis fulva along roadsides and stream banks in many parts of the country. It's one of the few garden plants to survive when farmsteads are abandoned.
The modern daylily, with its great variety of flower forms and colors, is an American creation. When A. B. Stout started breeding daylilies at the New York Botanical Garden almost 100 years ago, there were only a handful of varieties, all of them very close to the dozen or so wild species being grown at that time. Stout crossed wild varieties, and his success inspired the daylily boom we are in the midst of today. Since 1900 about 40,000 varieties have been named in the United States; 13,000 of them are still for sale.
Basic Features of a Modern Daylily
Daylilies are categorized in several different ways. Deciduous kinds go dormant in frosty weather, evergreens can tolerate frost and grow all winter in mild regions, and there is an intermediate group called semi-evergreen. The rule of thumb is to avoid deciduous daylilies south of zone 8 and avoid evergreens north of zone 7. It's good advice, though there are a few varieties in each group that defy the rule.
Most daylilies have arching foliage that grows 18 to 24 inches tall. Some varieties have erect foliage. Some are as low as 12 inches and others reach 3 feet. Leaf color ranges from pale green to dark green with a bluish cast.
The height provided in nursery descriptions and on plant labels doesn't refer to the foliage but to the length of the flower stalk or "scape." There is no correlation between height of the plant and the length of the scape, though most hold their flowers just above the leaves. Flower scapes on the shorter varieties grow as high as 12 inches. Scapes of the tallest reach over 6 feet high.
Single daylilies have six petals. Double varieties have a second set of petals, often ruffled. Flower size ranges from 1 1/2 inches--the "miniature" varieties--to 8 or 9 inches across. The color range of daylilies has expanded to include everything but blue and pure white. Many blossoms are bi- or tri-colored. Many modern daylilies are called "tetraploids." They have twice as many chromosomes as the normal "diploid" varieties. These sturdy varieties generally have larger leaves, stalks, and flowers.