I've never known daylilies to require much, if any, fertilizer. I prefer to derive all my garden nutrient needs from a mulch of compost and that works with nearly any plant type. It is also a great way to add organic matter to a sandy soil. If you feel you MUST fertilize (and thanks to Miracle Gro, many feel that way, unfortunately), any all purpose fertilizer, granular or liquid, will suffice.

I always use fish emulsion and often add alfalfa meal early on, before blooms begin.

kay