I had red yucca for a couple of years..it just lingered here...I'm too far north for it. Pentstemon(except the hardy varieties), have never wintered over for me. I have tried pushing my zone over the years and finally just come to the decision that it just isn't worth it for me. Lots of H-bird flowers you can grow in your own zone, and ultimately, they will grow and bloom much better for you and the birds.