Question
are they to bloom all season?  do you deadhead them?

Answer
Today's Daylilies are nothing like the ones your mother used to grow. The top seller in this genus, Stella d'Oro, wasn't invented until 1975.  There have been HUNDREDS of different hybrids over the last 25 years.

Yet, Stella is the world favorite.

Its high-energy blooms are the main reason.  But flower output does not lie with Stella genes alone.  Soil fertility, plant vigor, light intensity and daylength all play a role in how close any of this hybrid comes to meeting its own gold standard.

Daylilies also take a mid-summer sigh between flushes of blooming.

Deadheading never hurts, even on a Daylily.  Regular deadheading always results in a more vigorous plant, no matter what you're growing.

Bottom line:  If your Stella d'Oro gets lots of Sun and rich Soil, it can be expected to burst into bloom all Summer, with a few short blinks in between.  Thanks for writing.  Your followups invited.

THE LONG ISLAND GARDENER