Daylily flower power! Late season care for the jewel of the garden | MSU Extension

From msue.anr.msu.edu 

"Experts agree that perennial gardens are better when the gardener has a “lean” approach on fertilizer. Many have witnessed the “feed ‘em and weep” syndrome by adding a bit too much nitrogen in the early spring only to be rewarded with a floppy mess in August.

On the contrary, the humble daylily (also known as color queen of the summer perennial display) tends to be a hungry plant which will benefit by a mid-summer top dressing of nitrogen-rich fertilizer."

Read further the article of Rebecca Finneran, Michigan State University Extension