|Daylilies should be planted in full sun to partial shade. They need at least six hours of sun a day in order to thrive and bloom. Daylilies do well under tall trees, such as pines, where they get strong but filtered sunlight. Pastel shades can take more sun than the reds and purples, which can fade, bleed, or change colors in the sun.
The best soil for daylilies is one that is friable, course enough to drain well, but with organic material added. Clay soils should have an addition of sand to help the soil drain, and organic material such as peat or compost. Sandy soils should have an ddition of loam and organic material to help hold water and nutrients.
Daylilies will survive without extra watering, but they will thrive on water. They will bloom more profusely and have larger blooms if well watered. During hot weather, they should be watered at least weekly with 1/2 to 1 inch of water. During bloom season, they should be watered twice weekly or more to sustain good bloom. Daylilies should not be planted too close to trees or large shrubs which can rob them of water. Likewise, daylilies planted on a slope or cut bank may lose soil moisture more quickly. In either of these situations, daylilies may need to be watered more often.
Daylilies do not require heavy fertilization unless grown in very sandy soils. Early spring and early fall applications of a well balanced fertilizer, such as 6-6-6 or 8-8-8 are widely recommended; however, some people use a higher nitrogen fertilizer to boost the plants just before blooming. Mulching around daylilies helps to prevent the emergence of weeds and to retain soil moisture. If a mulch of wood chips is used, the decomposition of the chips will deplete the nitrogen from the soil, and nitrogen will need to be added through fertilizer. A pine straw mulch does not rob the soil of nitrogen.
When planting daylilies, the hole should be a little larger than the roots. A mound of soil should be made in the bottom of the hole, the daylily roots spread out over the mound so that the crown is higher than the roots and the soil firmly tamped back in place, just to the top of the roots--no higher. It is better to plant the daylily a little higher than surrounding soil, as this helps with drainage, and if the plant settles, it will not be too deep. Daylilies planted too deeply do not thrive.
If new plants cannot be planted for several days, the daylilies will be fine as long as they are not left in sun. They hold up better in a place without air conditioning, such as a porch. Air conditioning dries out the plants very badly. If daylilies must be kept for longer than a week, their roots should be kept moist by wrapping in a breathable material, such as wet newspaper or wet straw. The daylilies may also be kept in a pail of shallow water (just covering half or all of the roots--not the foliage), with a small amount of bleach mixed in the water to prevent the growth of bacteria, which can cause rotting. If kept several days, the water should be changed frequently. Many people make it a practice to soak all new plants in bleach water before planting.
Pests that attack daylilies include slugs and snails, aphids, spider mites, and thrips. Usually, insects do not kill daylilies, but weaken them, cause yellow or brown foliage, and make some blooms distorted. Many people prefer to sustain a little damage than to use pesticides. Overhead watering of daylilies helps to keep aphids washed off. The addition of Palmolive green dishwashing liquid to a hose attachment and sprayed on the plants will help kill aphids. If chemical pest control is desired, Orthene is a good systemic presticide that can be sprayed on with a hose attachment. Or one can practice biological controls, such as releasing ladybugs and other advantageous insects into the garden.
Transplanting of daylilies can be performed in North Florida in Spring (March through May) and Fall (September through November). It is best not be transplant during the heat of the summer, but if new plants are purchased then, there are ways to improve their chances of survival. One way is to put the daylily and place it in the shade until Fall. Another is to plant the daylily in the shade and move it later. Or, the daylily can be planted in the full sun with a shade tent of some sort over it: a basket, crate, piece of plywood, filter cloth, etc. Daylilies transplanted in the heat of the summer are more susceptible to rot.
A daylily's merits should not be judged until it has become a mature clump, usually about three years. In a very young plant, flower size and the branching of the scape may not be truly representative of the plant. Also, some daylilies with flowers that are not especially distinctive can really put on a show when the clump has 10 or 12 scapes blooming at once. A daylily's bloom schedule may be thrown off by transplanting that first year, but the second year's bloom schedule should be true to that cultivar.