The daylily is one of the most undemanding guests of the perennial garden. Daylilies require little care in the way of pruning or fertilization. Give them a little compost mulch and some shade in the heat of the afternoon and they will bloom day after day all summer long. Some even re-bloom into early fall. A perennial hardy from zones 2 to 9, daylilies bloom in every color but blue. Once considered a weed, daylily is one of the most popular garden flowers.
Plant daylilies where they get morning sun and shade during the hottest parts of the afternoon. Pale pastel and deep-red-colored flowering plants can tolerate more shade, but all daylilies need at least dappled sun to bloom well.
Place daylilies in well-drained soil; they cannot tolerate soggy soil. Apply an inch of water a week and more frequently during dry periods to keep the plants blooming.
Divide daylilies when they become crowded and blooming decreases. Lift clumps with garden forks and pry fans apart. Propagate daylilies in the fall for the best results. Division improves air circulation and soil aeration, two conditions that can stress plants.
Mulch daylilies in the summer and replace with clean mulch in the fall to minimize insect activity; fungus gnats can be a pest in crowded clumps. Mix 1 to 2 inches of compost with peat moss or well-rotted manure.
Fertilize newly-propagated or transplanted lilies in late fall or early spring with a slow-release garden fertilizer with an N-P-K (nitrogen-phosphate-phosphorus) ratio of 6-12-12 or 10-10-10 applied at about half the rate recommended on the label. Feed plants in sandy or poor soil each spring.
Deadhead spent blooms to keep scapes looking neat and prevent seed formation. Trim scapes in the fall after they die. Trim raggedy leaves; they'll grow new ones. Cut dying leaves back in late fall to deny winter shelter to rodents and insects.