Q.Stella D’Oro Daylillies Leaves Are Turning Yellow From The Tips Down. Get Adequate Water And Sun. No Signs Of Bugs On Them.
Have only been feed Miracle grow fertilizer one time.
Certified GKH Gardening Expert
It could be environmental leaf scorch, which is related to hot, dry conditions. Increase watering to help with that, but it is more of an aesthetic issue.
A common disease of daylilies is leaf streak, and here is more info about that disease:
https://www.gardeningknowhow.com/ornamental/bulbs/daylily/daylily-leaf-streak-disease.htm
https://www.gardeningknowhow.com/ornamental/bulbs/daylily/stella-doro-daylily-care.htm
https://hgic.clemson.edu/factsheet/daylily-diseases-insect-pests/