There could be several reasons for this to be happening. The first that comes to mind is: Wet weather....are you having a lot of rain in your area? If so the roots could be rotting.
The second thing that comes to mind is.....do you have mice in your yard. They will chew on roots of perennials and shred them. This will also make you lose your plants.

I had baby's breath for several years and mine just died out too. I didn't really investigate it, just planted something else there. So it could just be a short lived perennial. Anyone else have any experience with this?

Sierra

I found this article...

http://www.ipm.iastate.edu/ipm/hortnews/2006/2-22/perennials.html

In it the baby's breath is listed as a short lived perennial.

I have had mine for about 8 years in the same spot. I hope I have many years left for it. It is really pretty with the Luxury Lace Daylily that is planted right next to it. They both bloom at the same time.

Brenda

Thanks to both of you. Yes, we've had lots of wet weather, but our soil is very sandy so water doesn't sit around too long. We live surrounded by woods so mice certainly are local residents. I'm going to check that website and see what they have to day. I guess it will always be a mystery.
Thanks again.