I simply must put in a word on daylilies different varities bloom extra early, early, midseason, late and very late so depending on which ones you select you can have bloom for a long season. Like Cindi said some of them rebloom even here in the north plus some of them also have high bud counts. There is not the variety in colors, color patterns or shapes of the blooms in any other perennial. There are daylilies in all price ranges many of them are not costly.
Check out this site
http://www.daylilies.org/ it is the AHS society brose around the site and enjoy yourself.