Daylilies grow best in moist, well-drained soil with full sun in most areas. In hot arid climates, care should be taken to plant the lilies where they are in shade during the hottest part of the day. Daylilies should be planted in soil that has a slightly acidic, high humus or organic matter base. Till the soil before planting and add fertilizer to slightly raise the acidity before planting.
Plant new daylily crowns anytime the soil can be worked. Add manure or compost to the soil and till. Crowns should be planted 1 inch below ground level. Cover with mulch or other organic matter to protect the young crowns from colder weather until the plant is established.
Add additional mulch in the late spring or early summer to reduce weeds growing in the daylily patch. Water the plants if needed to approximate 1 inch of water weekly. Daylilies have few pests, although aphids will occasionally feed on the flowers. These can be removed by using an insecticide soap spray.
Daylily clumps should be dug up and divided every 4 to 5 years. Spent flower heads should be pinched off after blooming to retard seed production and assure an equal or greater amount of flowers the next season.