The most effective weed control measures for the home garden are mulching and hoeing. Sanitation Proper sanitation measures lead to healthier daylilies. In the spring, dead foliage and debris should be cleared away from around your daylilies. During the growing season, damaged or diseased foliage should be removed. At the end of the bloom season, cut off the bloom scapes to within a few inches of the ground unless you are hybridizing.
Daylilies do have some pests, but many do only minor damage.
Aphids Daylilies have their own specific aphid which feeds only on daylilies. Aphids are most active in cool weather spring and fall in temperate zones, and all winter long in the subtropics. Controlling daylily aphids is not as easy as with other kinds of aphids, which are usually vulnerable to such soft controls as soaps. In order to reach daylily aphids inside the fans, a pesticide with at least a mildly systemic action is needed. Do not use the pesticide Kelthane, which is known to harm daylilies.