One year, a couple of my daylilies did not bloom as expected. I found his quite puzzling as they had bloomed very nicely in previous years. I had done everything I thought was important for good daylily blooms; fertilizer, plenty of water, lots of stable sweepings as mulch. The plants looked good, the foliage was nice and green, just no blooms. I was stumped.

In the fall, I dug them up in order to move them. Much to my surprise, I found that the daylilies had two crowns, one about 1.5 inches above the other (the crown is where the roots are attached to the plant). I noticed that the lower crowns were actually about 3 inches below the level of the soil. The daylilies were planted way too deep and had stopped their normal growth cycle to re-establish a new set of roots at the proper soil depth. That's why I didn't get any blooms. This really shows that proper planting depth is very important.

Note: Actually, I had not planted the daylilies too deep. They were planted at the proper depth, but repeated applications of mulch right up to the plant added the additional soil depth as it decomposed.

More common reasons for failure to bloom: