Hi Anu these plants are not what you are thinking--no dianella and no salvia, you are seeing red pine-leaf penstemons and striped bearded iris. Colorado-adapted plants that prob wouldn't be as happy for you. You're right, dianella isn't hardy here, and we grow many salvias here but mostly very different species from what thrives in zone 7-9.

Wow, those iris look so similar to dianella! I think I could reproduce this with similar looking plants here in hot, hot Houston. One more question, what are the blue flowers and the big clump of burgundy way at the end?