DAYLILY (Hemerocallis) CULTIVATION

Today's daylilies come in a variety of shapes and sizes with clearer colors except for pure white and pure blue. Hemerocallis is a botanical name derived from two Greek words that represent "beauty and day" or beauty for a day. Most daylily blooms last just for one day, opening in early morning and remaining open throughout the afternoon into early evening. There are exceptions. Usually, several flower buds form on each plant in various stages allowing for a succession of bloom for periods from a few to several weeks.

In upstate New York, extra early varieties begin blooming in mid-June with the main bloom peaking mid-July. Late varieties extend bloom from late July into August with a few rebloomers and very lates lasting to frost. In the south, many daylilies have a rebloom cycle where there may be time for the plant to send up new scapes. In the north this is not as common although we are beginning to see more daylilies showing an "instant rebloom" characteristic by sending up rebloom scapes while the origininal scapes are still carrying bloom. Late rebloom scapes may appear but many without sufficient time to bloom before frost. Experience will determine which scapes have a chance to rebloom and which ones should be cut close to the crown to save the plant's energies.

WHERE TO PLANT: Daylilies prefer full sun but will tolerate some shade. It is best to place them so that they will receive at least five to six hours of full sun each day. Purples and reds may benefit from afternoon shade. Daylilies should not be planted near large trees where there is root competition for available moisture and nutrients. Soil should be relatively well drained to eliminate standing water. Daylilies can tolerate much water and need copious amounts to perform well.

WHEN TO PLANT: Daylilies should be planted after the last date for spring frost. If new plants arrive early they should be protected from late spring frost. If it is not possible to get them in the ground within a day or two of arrival, plants can be held in damp sand or moist potting medium. Spring planting is preferable as it gives the new plant time to develop a strong root system to carry it through the first winter. If it is necessary to plant in fall, put it in the ground at least six weeks before killing frost. Then, after a killing frost, mulch it well. Fall planting of southern grown plants is risky in northern climates as they are difficult to harden off before frost.

Bare root plants can be put into a pail of water. This should be for a few hours but can be over night or a few days if need be. The foliage should be cut back to about 6 inches above the crown to reduce the transpiration loss. Extra-long roots can also be cut back to about four or six inches from the crown without hurting the plant.

HOW TO PLANT: Loosen the soil to a depth of at eight to ten inches. Compost can be mixed in. The planting hole should be wider than the root spread. Plant so that the crown will be just below the top surface and slightly above the surrounding surfaces to allow for settling. Do not excessively compact the soil after planting to allow for good aeration, water percolation, and rootlet formation. Water liberally to settle the plant in. Daylilies are relatively shallow rooted plants. Freshly planted plants tend to be prone to soil erosion exposing the roots. This should be avoided and new plantings carefully observed for this problem. This is especially true for late fall plantings. Remember to label the plant.

Clay soils and compacted soils will limit the root spread of the plant. This results in the cramping of new crown development that will decrease overall plant performance. Amending these soils with good compost will allow the roots and crown development to spread out more. The plant will increase faster and be much easier to divide and will not need to be divided as often.

Space daylilies at least 18 to 24 inches apart. This allows ample room for growth without crowding. It may look sparse but in a year or two the reason for this spacing will become apparent. Try to leave a daylily undisturbed for at least three years.

WINTER PROTECTION: Frost-killed foliage gives a small amount of protection to the crowns. If a winter mulch is desired, a light covering of wheat straw, pine needles or similar mulch should work well.

DIVIDING: Division of daylilies can be made any time after last day of spring frost to about six weeks before first day of expected fall frost. The secret of success is to get the divisions back into the ground as quickly as possible, keeping roots covered and plants well-watered until established.

A daylily clump may not need to be divided before 3 to 5 years. Decreased bloom is one indicator for the need for division. A freshly dug daylily should have its foliage cut back to about six to eight inches above the crown.

The divisions can be single, double, or multiple fans depending upon how the original clump comes apart. Compacted crowns are difficult to divide. They are best cut apart with a sharp knife. Large compacted crowns can be forced apart with the point of a well-placed shovel and a heavy foot. Each fan must have its own collection of roots. Double fan divisions will clump up faster than single fans.

WATERING: Daylilies thrive with ample watering. An inch of rainfall per week is considered minimum. Without sufficient watering, bloom production will diminish. Water is needed most in spring and summer when growth is rapid and blooms are being produced.

FERTILIZING: Daylilies thrive in a wide range soil pH with approximately 6.4 being the optimum. Established plants will benefit from a spring application of a good fertilizer such as 5-10-5 or 5-10-10. Older and larger established clumps may require a little more fertilizer due to soil depletion. Foliar applied fertilizers are ideal for daylilies. Gardeners should avoid high nitrogen fertilizer and late summer applications as they may lead to decreased bloom and lack of winter hardiness respectfully.

Complied by Tom Rood, past American Hemerocallis Society Region 4 President, Publicity Director/Newsletter Editor and Master Gardener- Yates County Cornell Cooperative Extension, founder FINGER LAKES DAYLILY SOCIETY. Co-owner of Grace Gardens, Penn Yan, NY.

Acknowledgments: Leslie Hegeman, Past President, Long Island Daylily Society. Nassau County Cornell Cooperative Extension. Daylilies and The Beginner's Handbook 1991 Revised edition. American Hemerocallis Society.

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Updated: February 1, 2019