Dusty Miller is a perennial plant. What you're observing is the reproductive stage, when it elongates and flowers, then sets seeds. I believe that most people keep DM clipped back so that it remains in the juvenile stage. The flowers are kinda pretty, though. It probably won't overwinter in your climate, though I am not certain about that. It'll go on and on in semi-tropical zones.

Whether is over-winters depends on the DM. I have some that have been growing in my yard for a few years in zone 5. I've never had mine go to seed so I can't say if it will re-seed naturally but I have my doubts. If you get matured seeds, you could always harvest them and grow them yourself.

Thanks for the information. I hope they survive but I am enjoying them while they are alive. It will be interesting to see what the flower looks like. They sure grew well.

I usually cut off the seed stalk to prevent the flower. Here they reseed in my garden over a wide area plus the plant is perennial. Al