You haven't given much information other than sun. Is it well mulched? Does it get ample moisture? What is the soil like? Do you have problems with voles or other burrowing critters that like eating plants? Where are you? I haven't had issues with my alpina and macropetala varieties other than voles eating them, but they may have more problems in areas with different weather. My Joe Zary is only a year old, but did fine last summer and even had a few flowers.

IF it were mine I would cut it back to six inches and toss a handful of alfalfa pellets around it.