Using the wrong fertilizer and not planting daylilies in the proper location can prevent blooming. Overcrowding daylilies, planting them at the wrong depth and disease can also prevent blooming.
Plant daylilies in a location where they receive full sun. Daylilies require six full hours of sunlight each day to bloom efficiently. Protection from the afternoon sun keeps the flowers from fading. Ensure the climate matches the type of daylilies planted. Some daylilies thrive in colder conditions, but warmer varieties are damaged due to cold weather. Choose a proper fertilizer. Fertilizers that are high in nitrogen produce more leaves and fewer flowers. Fertilizers low in nitrogen and high in phosphorus encourage flower growth.
Plant daylilies so the crown of the plant is at the surface of the soil. Crowns planted deeper cause the plant not to set flower buds. Avoid crowding daylillies or they don't bloom. They should be divided every three to five years to reduce overcrowding. Divide daylillies in the spring or early fall season. Avoid dividing during the summer, and avoid dividing within six to eight weeks of the first frost. A disease known as "daily rust" affects daylilies. This disease causes them to stop flowering and causes the leaves to turn brown.