University of Vermont Extension
Department of Plant and Soil Science


Daylilies                                               OH 33

Sinclair Adam Jr., Former Graduate Assistant

Hemerocallis (daylily) is not really a lily at all, but is related. Lilies are bulbous plants, while daylilies have fleshy roots.
True lilies also have leaves borne alternately or in whorls, while the daylily has leaves attached to a central basal
crown.

Out of some 15 original species of Hemerocallis imported from central Europe and the Orient, few are commercially
produced today. Over 20,000 hybrids do exist, and improvements in plant habit, flower form, and color have made
these hybrids quite desirable as garden plants. Although daylilies tolerate poor care or neglect because of their tough,
resilient nature, best growth and flowering are obtained by using the following cultural procedures.

Soil: Daylilies are fleshy-rooted perennials that prefer a well-drained soil. Sandy or heavy clay soils can be improved
prior to planting, to a depth of 12 inches, by incorporating amendments such as sphagnum peat moss, bark mulch, or
composted leaves. Add equal parts of such amendments to parts of soil.

Light: Most daylilies will grow well when they receive at least 6 hours of sunlight daily. Some bright colors fade in full
sun, but in general the plants prefer bright, sunny locations. Flowers will open to face the sun or bright light, so place
them with this in mind. A warm, sheltered, south-facing site may speed up bloom time slightly, and will yield good
results.

Watering: Daylilies prefer moist soil and should be watered if rain is insufficient. Irrigations should be deep rather than
shallow and should be gauged to the site's requirement. Watering overhead late in the day may damage tomorrow's
flowers, so timing is important. Also, it is advisable to water in the morning rather than evening, because moisture on
the foliage overnight may encourage leaf diseases. Mulching is useful in conserving water and controlling weeds. A
third to one half more nitrogen should be added to offset consumption by decomposing mulch.

Fertilizing: For efficient liming, a soil test should be made prior to planting. Add lime if needed to raise the soil pH to
5.5 to 6.5. Daylilies are voracious feeders when they are actively growing, and special care should be taken to see that
the fertility and moisture levels are sufficient prior to bloom time. Granular fertilizers are most frequently used (such as
10-10-10 at 3 pounds per 100 square feet), but liquid-soluble and foliar-applied fertilizers can also be used according
to label directions.

Pests: Although daylilies are not bothered by many insects and diseases, some pests may cause problems. Mites can
cause injury when plants are in full sun and get dried out. Thrips and aphids may damage flowers, especially the darker
colored cultivars. These can be controlled by timely spraying, using pesticides available at garden supply stores
according to label directions. Care should be taken to see that plants are well watered and air temperatures are
between 50 and 80 degrees F prior to applications of chemicals. Fungus diseases are not very prevalent on daylilies,
but those that may occur can be prevented with fungicides also available at garden supply stores.

Mail order plants: Plants received dry should be soaked for 12 hours prior to planting. If it is not possible to plant
immediately, plants may be stored successfully for a short period of time (2 to 3 days) in a cool garage or basement.
The roots should be placed in moist peat moss or sand. Any signs of mold or fungi on the roots should be dealt with
swiftly. A dip of the entire plant in a solution of fungicide for root rots should help correct the problem.

It is best to plant daylilies as soon as practical. Northern-grown daylilies can be planted outdoors anytime from April 1
to October 1. Those from southern nurseries may be injured by frosts if planted too early or too late.

Catalogs list daylilies as D (dormant), SE (semi-evergreen), or E (evergreen). Dormant daylilies stop growing and
drop their leaves when the days are short, much like deciduous trees. Evergreen daylilies are not affected by short
days and hold their foliage until it is literally frozen off during the winter. Semi-evergreens are somewhere between
dormants and evergreens. Many evergreen daylilies are perfectly hardy in the North, but the foliage may be somewhat
unattractive in early spring.

Planting: Daylilies should be spaced 18 to 24 inches apart and should be planted so that the crown (the point below
which roots begin) is no deeper than 1 to 2 inches below the soil surface. One method of planting that has become
successful is the "cone" method, where a hole is dug and a cone of soil is made in the hole. The plant roots are spread
over the cone. The hole is then filled with soil and packed lightly to eliminate air pockets. Any system of planting is
acceptable as long as the roots are in good contact with the soil and the plant is at the correct depth. Watering after
planting is advisable because this will further improve soil-root contact.

Dividing: Daylilies should be divided when clumps become too thick. This will occur with most cultivars when they
have been planted 3 to 5 years. Best flowering usually occurs 2 to 4 years after planting.

Landscaping: Daylilies may be planted singly, in masses, or in mixed border arrangements. Both fragrant and
non-scented cultivars exist. The entire color spectrum (except true blue and true white) is currently available and all
ranges of heights are possible as well.

Bloom time varies from June through October, depending on cultivars. Catalogs usually list EE (early May to early
June); EM (early mid-season: late June and early July); M (mid-season: mid-July); LM (late mid-season: late July and
early August); and L (late August and September).

Some of the best garden cultivars are as follows: Bitsy, Butterpat, Green Flutter, Mary Todd, and Stella de Oro
(yellow and gold cultivars); Elizabeth Yancey and Yesterday Memories (pink cultivars); Apple Tart, Ed Murray, and
Red Rum (red cultivars); Hope Diamond and Joan Senior (near white cultivars); Little Grapett and Russian Rhapsody
(purple cultivars); Prairie Blue Eyes (lavender cultivar); and Bertie Ferris and Ruffled Apricot (orange cultivars).

No matter what color, height, or season of bloom, daylilies are one of the most reliable, diverse, and durable of the
perennial flowers.


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Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the United States Department of Agriculture. Lawrence Forcier, Director, UVM Extension System, Burlington, Vermont. University of Vermont Extension System and U.S. Department of Agriculture cooperating, offer education and employment to everyone, without regard to race, color, national origin, sex, religion, age, disability, political beliefs, and marital or familial status.

Last reviewed 2003