Plant and grow daylilies by choosing a location with access to full sun, using well-drained soil, watering them regularly and feeding them once a year. Choose a planting site that doesn't have any bushes or trees nearby and has only light shade, preferably in the afternoon. Too many plants nearby can leach the moisture and nutrients that daylilies need to survive from the soil.
Prepare the planting site by loosening the top 12 inches of the soil and working in compost or well-rotted manure. Dig a large hole that is wider and deeper than the plant's rootball, as the crown of the plant needs to be planted just below the soil line. Place the roots in the hole, and loosen them so that they aren't crowded.
Arrange the plant so that the crown of the plant, where the stem meets the roots, is 1 inch below the soil line, and fill in half the hole with soil. Tamp down the dirt to get rid of any air pockets, water it well, and finish filling the hole. Press the soil down again so that it dips slightly around the plant.
Water the plant deeply at least once a week at the base of the plant, and avoid getting the foliage or blossoms wet. Add a layer of mulch around the soil to keep it moist and inhibit weed growth. Fertilize the daylilies once a year in the spring unless the soil is sandy or poor; in that case, fertilize more often.