Emmi, if I remember correctly your bog is fairly new. It can take several seasons for some plants to adjust to our brutal climate and some just never really do. Hybrids tend to acclimate better than most species here but give it a few seasons before you start thinking thst something is wrong. The bogs I have here were put in around 5 years ago and there are still several plants that never reach their full potential due to the long, cold winters and short growing season. S.minor hates it here as do some forms of psitticina and leucophylla. I've also found all forms of S.rosea and S.rubra jonesii var. viridescens to be impossible to grow outside all year here and I've stopped trying all together.