It has been a long time since I stopped using Safer's. The Safer's instructions (according to a web download) indicate that the same rate is used both on indoor and outdoor plants.
The daylilies were growing indoors over winter in large pots under lights. They would have had aphids from near the start of their growth and that would have been several months before flowering. Basically all their foliage would have been produced under the lower light intensity of indoor fluorescent lights. I assume they would have responded by producing shade type leaves instead of sun type leaves. Perhaps it is possible that such leaves are more susceptible to damage than the leaves produced outdoors in direct sun.
