Sorry to hear the deer have found your daylilies. Along with the milorganite if you are in an area where noise would not be a problem you could try leaving a radio on outside in the garden all night. Deer do not like strong smells or noise, they can't smell or hear a predator approaching.
We are in a rural farm land area and the deer are still nervous when around homes, it doesn't take much to scare them off or remind them this is not a deer friendly property. The radio placed inside a rubbermaid tub tipped on it's side to keep the rain off and also funnel the sound into the garden is one thing I use during bloom time and normally works well. Another option or if you have a more determined group of deer around is a monitor for movement (driveway monitor with in house chime) they can be placed to detect movement in the garden, then a dash outside during the night with something loud. I use a big old antique wooden noise maker my Grandfather made, not sure what he used it for.
