Once regarded as a roadside weed, the daylily has found its way into many Colorado perennial gardens.  Despite humble beginnings, modern hybridized daylilies have become a mainstay of hot, summer flower gardens.  Easy to grow, daylilies come in a wide range of colors, shapes and sizes. With a fairly long blooming season, daylilies are relatively pest and disease free, drought resistant and tolerant of most soil conditions.

Like its name Hemerocallis, "beauty for a day", the individual daylily flower lasts only one day. However, a single plant may produce over 100 flowers, extending a plant's bloom period for several weeks.  More than 52,000 cultivars have been registered.  Over 12,000 are available commercially, with periods of bloom from very early to late in the season.  Daylilies can be blooming with iris in spring and continue into fall with chrysanthemums.

Daylilies are members of the Liliaceae (lily) family.  Originally from Eurasia, the lemon daylily (yellow) and the tawny daylily (orange) were brought to the New World by colonists and were popular farmyard plantings.  The tawny daylily spread to roadsides, thus leading to its other common name, "ditch lily."

Most daylilies are deciduous (foliage dies to the ground each winter), although some are semi-evergreen or evergreen.  Deciduous varieties are commonly referred to as dormant.  The arching foliage consists of long linear leaves that grow 1 to 2 feet tall.  Leaves are a rich green color.  The erect, leafless flower stalks--called scapes--rise from the crown of the plant and extend above the foliage.  The scapes of most varieties range in height from 18 inches to 5 feet tall.  Five to 30 or more flowers are present on each flower stalk.   Flowers range from less than 2 inches across, for the miniature varieties, to over 9 inches.

Flowers are available in almost every color, except blue and true white.  Some varieties have attractive eyes and throats.  Others are polychromes, with blends of related shades, and bi-color and eyed flowers.  Edged flowers occur when the segment edges are either lighter or darker than the segment color. Many of these colors and characteristics are the result of extensive hybridization.  The root system of daylily plants varies from an almost fibrous type to the common fleshy type.  This fleshy root system, in part, differentiates the daylily from true lilies that grow from bulbs.

Growth needs

Daylilies grow best in partial shade to full sun.  Although they are known for their tolerance of poor sites, they will perform best in soils that are well drained and possess abundant organic matter.  If fertilized heavily, foliage will be overgrown and flowering will be poor.  One application of a complete fertilizer, such as 10-10-10, in early spring should be adequate.  Water once a week to a depth of 8 to 10 inches and more often during prolonged periods of drought.  Mulching is beneficial.  Winter mulch applied in late fall should be used on newly transplanted daylilies.  Once they are established daylilies usually do not need winter protection.  Some of the evergreen varieties are less winter hardy and require continued winter protection.  Winter mulches should be light and airy.  Coarse materials such as straw work well.

Just as other plants in the garden need regular clean up, daylilies are no exception.  Remove dead foliage and debris from plants in early spring and late fall.  Check plants regularly during the growing season to remove damaged or yellowed leaves.  Some daylilies produce seedpods after the flowers fade, if left in place.  Unless you want to experiment with seedling plants, faded flowers and flower stalks should be removed before seeds are produced to ensure that all of the plant's stored food reserves go to the roots, so the plant will make a good showing next year.

Propagation

Daylilies can be propagated through division or by hybridizing.  Division of large clumps is an easy way to add quantity to the garden.  Trading and sharing daylily divisions is a great way to add variety to your collection.  Clumps can be divided when they become overcrowded, usually every 4 to 6 years, by separating the plant into rooted segments, each with 1-2 shoots.  This division is referred to as a fan.  Because the root system is so vigorous, you may need to use a spade or fork to get the pieces apart.  Daylilies can be divided in spring as new growth is emerging or during September.  Planting may also be done in the very early spring.  Avoid dividing blooming plants.  When planting divisions or newly purchased plants, the hole needs to be large enough to allow the roots to spread out.  A small cone of soil should be made in the center of the hole, with the division placed on top with the roots fanned outward and downward.  Carefully work the soil around the roots.  Set the plants so that the crown (the point where the roots and foliage meet) is about an inch below the soil surface.  Tall cultivars should be spaced 24 to 30 inches apart, with smaller types 18 to 24 inches apart.

More adventurous gardeners can become back yard hybridzers.  In the plant world, Hemerocallis is one of the easiest plants to propagate by crossbreeding.  Hybridizing is taking the pollen of one plant and crossing it to another flower to produce seed.  At the center of the daylily flower are typically six stamens or anthers (male parts) and one pistil or stigma (female part). The pistil is the center protuberance of the daylily that extends out about 2-3".   The powdery substance at the end of the stamen is the pollen and it should be taken from one flower and placed on the tip of the pistil of the other flower.  The easiest method is to pick the whole stamen with pollen attached and brush it across the top of the pistil.  The best time to hybridize is as soon as the pollen has dried and become fluffy, usually about mid-morning. The art of hybridizing lies in picking the right parents. Serious hybridizers tag each cross on the plant, keep extensive records and plan every cross based on traits of the cultivars used. The convention for keeping track of crosses is: Name of POD parent X name of POLLEN parent.

Allow the seed to develop (do not remove the spent flower).  If the cross was successful, within 3 days there will be a tiny green nub right at the spot where the flower was attached.  Small seed pods begin swelling a few days after pollination.  The seedpod will grow to a length of 1/2"-2".  As seedpods ripen, after approximately 40-60 days, they turn yellowish and then brown.  Harvest the seed as pods begin to split open. Remove the seeds from the pods and let them air dry overnight. Then put them in air tight containers and place in the crisper drawer of the refrigerator over winter.  Sealed plastic bags or empty 35mm film containers can be used for this purpose.

To accelerate the growing season, seeds can be started indoors in either flats or pots and grown under lights during the winter months.  When the ground warms up outside in the spring  the transplants can be moved outdoors.  Plant spacing is dictated by the amount of space available and the number of seedlings you plan to grow. With limited space, plant close together - approximately 4 inches apart in rows about 8-10 inches apart, otherwise plant about 12 inches apart in rows about 12 inches apart.

Seeds can be planted directly in the ground.   Remember that seeds require fairly warm soil temperatures for good germination. Plant your seeds between 1/4 and 1/2 inches deep. Water frequently so that seeds don't dry out.  Keep the beds weeded and water them regularly. Applying a balanced liquid fertilizer on a regular basis is also beneficial.  Occasionally a few plants bloom the first year, however in Colorado, with shorter growing seasons, it may take as long as 2 to 3 years for them to bloom.  High heat is a notorious cause of failure to set seed. Other problems include; sterile pollen, lengthy or non-functional pistils, and ploidy mismatch--typically, tetraploid crosses to diploids will fail.

Since the mid-1970's, back yard hybridizers and entrepreneurs have been changing how daylilies look and perform.  Dozens of American hybridizers are recognized for their distinctive approaches to form, color, plant health and performance.  High bud count is commonplace today.  Repeat flowering has been bred into many new cultivars, offering more than one cycle of bloom within a growing season. Colorado gardeners who browse nurseries and catalogs for contemporarily bred daylilies will discover thousands of enticing varieties or make the daylily variety of your own by hybridizing.  For more information about daylilies visit the National American Hemerocallis Society's website at www.daylilies.org

Types of daylily flowers

Triangular flowers have petals that are extended fully, but with sepals curved under.

Spider flowers have long, narrow petals and sepals whose tips may curl under.

Flat flowers occur when both petals and sepals show no tendency to curl.

Recurved flowers have their segments ends tucked under.

Pinched flowers appear to have ends of the segments pinched together.

Ruffled flowers have wavy edges on their petals and sepals.

Double flowered varieties occur when the reproductive parts manifest as an extra set of petals.

Q: Last year we had quite a few worms in our apples.  This year we sprayed with an insecticide right after the tree finished blooming.  We read that we should spray again around mid-summer for another generation that might be more numerous than the first.  Is there some way to know when we should do this?

A:  Apple worms are the larvae of a moth called the codling moth.  There are two or three generations per year.  The first generally takes place in mid-May and the second around mid-summer.  The eggs for the second are laid directly on the apples.  The larvae then tunnel into the apples.  To monitor peak flying times and therefore, optimum times for spraying, pheromone traps are available and can be hung in the trees to tell you when the moths are flying and laying eggs.

Q:  I have sucker-sprouts from my aspen trees coming up in my lawn. What can I do to get rid of them?

A:  The roots of trees can become quite wide-spread as they grow, with most of them generally located within the top 20 inches or so of the soil surface.  If some happen to be close to the soil surface, they can send shoots up into the lawn.  These shoots are connected, by the roots, to the original tree.  The application of a herbicide to these shoots could travel back through the roots into the tree and ultimately damage it.  A better way is to use pruners and regularly snip off these "sucker sprouts" below the soil surface as they appear and before they get too large.

Q:  Some of my tomatoes are getting dark, soft spots on the ends.  What is this?

A: This is a condition called "blossom end rot".  It can be caused by fluctuating moisture levels in the soil as a result of improper irrigation or by very dry weather.  Other causes might be over-application of nitrogen fertilizer or some disruption to the roots.  It can usually be prevented by applying the correct amounts of nitrogen and by mulching around plants to conserve moisture.

Have a hard time knowing how to pronounce some of those plant names?  Here are a few I'm always tripping over.  Agastache (ag-ah-STASH-ee), Aquilegia (Columbine) (a-quill-EE-jee-ah), Nicotiana (ni-KO-shi-ay-nah), Kalanchoe (kal-en-KO-ee), and Kniphofia (nye-FO-fee-ah)

Deadheading (removing spent blossoms) is a common practice to keep annuals blooming all summer and it can also help perennials.  Some perennials may rebloom from lateral buds if the terminal bud is removed. Others, like daylilies, just look better and give developing buds room to grow.

Planttalk Colorado™ is a free 24 hr. toll free automated telephone service provided by Colorado State Cooperative Extension, Denver Botanic Gardens, and Green Industries of Colorado.  This service is also available on the web at www.planttalk.org for more information on over 400 gardening topics and links to additional resources.

Divide and replant bearded irises that have become crowded and are not blooming very well.  Use a spading fork instead of a shovel to avoid cutting the tubers.  Cut off dead or mushy parts and trim the foliage to about 6".  Amend the soil and replant in a sunny, well drained location.

The authors have received training through Colorado State University Cooperative Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County.

Gardening and Insect Fact Sheets are available on-line by clicking HERE.

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This page updated:  July 14, 2003