Daylilies are hardy perennial plants with fibrous roots that grow in clumps and can be divided once they have been established over several years. The botanical name for the daylily genus is Hemerocallis, which can be translated from the Greek to mean "beauty for a day", and refers to the fact that each bloom lasts just one day. It should be noted that, while each bloom may last only a day, each plant can have many flower buds on one scape (leafless stalk), and many scapes in each clump of mature plants. This results in bloom periods that can continue for several weeks. In addition, many cultivars have more than one blooming period in a season. It is possible, by choosing early, mid, and late season cultivars, to have daylilies blooming from early spring until late fall in your garden.
Daylilies come in a multitude of colors, shapes and sizes, making them a versatile addition to any garden. The flower scapes range in height from less than a foot to seven feet tall! They are drought tolerant, and can also survive all sorts of inclement winter weather conditions, growing back vigorously each spring.
When to plant
Daylilies can be planted any time the ground is sufficiently workable, however our first preference would be to plant in spring, which will allow ample time for roots to become established before the onset of winter. Another school of thought recommends fall planting since ground conditions (having warmed throughout the summer) will promote rapid root growth, allowing plants to establish themselves quickly. Roots will generally continue adding new growth in soil temperatures ranging from 2oC to 18oC.
Where to plant
Daylilies prefer full sun although may tolerate partial shade. They do best in well drained soil with a slightly acidic pH (6 - 6.5), but commonly tolerate a range of soil types and still perform admirably. If you have poor soil it can be amended with organic materials (compost; well aged horse, sheep or cow manure) over time to improve your garden's health and performance.
How to plant
If you are receiving your plants bare root by mail order it is best to soak the plant, fully immersing the roots, for a couple of hours before planting. Work the soil in your planting area so that it is loose to at least 12 inches in depth and 18 inches in diameter. In general the hole should be larger than the root mass. Add compost, good garden soil, or well rotted manure to the planting soil. A little bonemeal added in at this time will encourage strong roots.
Once you have the soil in your planting hole prepared mound up the soil at the centre of the hole so that the peak of the mound is about 2 inches below the surrounding (undisturbed) ground level. Place your bare root daylily so that it is centered on top of the mound in the hole with the roots spread out and draped down the sides of the mound. Fill around and on top of the roots, firming the soil over the roots as you go and gradually filling the hole so that when the hole is full and the soil is firmly packed in around your new plant the level of the soil in the hole is 1 inch lower than the surrounding (undisturbed) ground level.
Container plants can be planted in a prepared hole in much the same way although you can use the soil from the container, gently loosening it around the plant roots if necessary. You may need to loosen the roots and spread them slightly, especially if the plant has been in the pot for an extended period of time prior to planting.
It is important not to plant your daylily too deep. As a general rule there should be about 1 inch of soil above the crown of the plant (i.e. where the foliage and the roots meet). The soil should be just deep enough to cover the non-green portion of the fan. Water thoroughly.
Daylilies will perform best if given at least an inch of water a week during the growing season. You will have more scapes and buds, the flowers will be larger and will have better colour if you provide ample water just before and during the blooming period. In addition, if you provide adequate water, you will have greater success with reblooming cultivars, which can extend your season considerably.
We prefer the use of organic fertilizers whenever possible. Using composted organic matter mixed with aged horse, sheep or cow manure in spring or fall will provide your plants with the nutrients needed to maintain healthy foliage, produce the best flowers and have strong roots. Properly aged organic garden compost can be applied liberally as this will improve soil structure and overall health on a permanent basis, which will not be the case if you use only artificial fertilizers. However, if you don't have access to composted materials you can use a general purpose, slow-release fertilizer in the spring and a high potassium fertilizer in the fall.
Mulch will protect your plants in the winter and keep the soil cool and moist in the summer and will also inhibit weed growth. Leaves, straw, bark mulch and dried grass clippings can all be used for mulching. Two to four inches of mulch is recommended. Where the ground freezes in the winter you may wish to mulch more heavily, especially in the first year after planting your new daylilies, to help them overwinter.
Removing the spent blooms ('deadheading') and the scapes that are finished flowering from your plants will enhance the look of your garden. When flowering is over for the season it is a good idea to tidy up the foliage on the Evergreen and Semi evergreen daylilies, which can then be left until new foliage begins to emerge in the spring. Decaying foliage from Dormant varieties should be removed as soon as possible from around plants to discourage slugs and snails from inhabiting it. This will leave your garden tidy and ready for spring.
Vigorous growers may need dividing in as little as 3 years, while others won't need division for 4 or 5 years or even longer. Small clumps of daylilies (i.e. less that about 10 fans) are usually easy to divide. They can be removed from the ground using a garden (spading) fork being careful to leave the roots intact as much as possible. Gently remove soil with your hands or wash the soil away with a hose to expose all the roots. A large sharp knife, pocket knife, or screwdriver can be used to cut between the fans for divisions. It is best to divide into groups of 2-3 fans, however single fans will also grow, providing roots are intact.
For large clumps that are difficult to divide you can use two spading forks placed back to back and plunged into the center of the clump that has been dug out. Then force the forks apart separating the clump into two. Further divisions can be made as necessary either with the spading forks or with a sharp knife. Older portions of the roots may be removed before replanting, as this will encourage new root growth.