Opps, I just realised this is on the daylilies forum so you were referring to daylilies specifically.
My way of fertilizing daylilies. Each spring I put out the bagged fertilizer. My favorite to use on the daylilies is FlowerTone. But if you can't find that then PlantTone is good to use also. If I am really ambitious I throw alfalfa pellets out in the daylily and rose beds.
Then I don't fertilize until mid summer. After bloom season. Which is when I get out the Neptune Liquid Fertilizer and really drench those dayliliy beds. That's it, I don't do anything else as far as fertilizer is concerned.