Soil and Preparation:

Daylilies flower best when planted in full sun (6 hours/day), with moist, yet well-drained soil. Daylilies will grow in a wide range of soils, from sand to heavy clay, and in a wide range of soil pHs. Clay soils can be improved by the addition of compost, humus or peat moss, or sand which will help make it more friable. Sandy soil will benefit from the addition of compost, humus or peat moss which will serve to increase water retention. Amend the soil withcompost before planting. Space plants 12 to 18 inches apart and plant so the crown is about 1 inch below the soil surface. Water well and mulch with bark or straw to conserve moisture and prevent weeds from growing. 

Planting:

Dig a hole large enough to accommodate the root mass, usually about 6-8" deep. Once the hole is prepared, place the daylily upright, without cramming it into the space.  Holding it so the crown (top of the roots) is about one inch below the surface of the ground, spread the roots out in the hole and loosely push soil over the roots until the hole is nearly full. Press the soil down around the roots, without covering any green of the plant. Leave a slight depression, or water reservoir, around the plant, about 1/2" deep.

Watering:

Watering is most important in spring when the plants are making scapes and buds, and in the summer during the bloom season. Daylilies benefit more from deep watering, which reaches 8 to 10 inches into the soil, than from a succession of brief, surface waterings. 

Fertilization During Growing:

They do not require fertilization other than a yearly addition of compost.