I have a small beach lot and grow in boxes. I've had 80 daylilies for the past 4 years. This fall I'm contemplating reducing the number to 75 or below. If they don't thrive and don't put on a show ... out you go beast! My back yard is 35 ft deep and 80 ft across. Half is shade and half is sun. The daylilies have sun, but big palm trees give them shifting shade. I might lose some bloom to shade, but the daylilies certainly grow better! There is a big box in the front and that's included in the total numbers.
Just have to say....my beach sand will not support daylilies because it won't hold water no matter how much organic stuff is added. The organics are absorbed into the sand in less than a year so boxes are the only way I can grow plants that are happy.