Keep in mind that Rosemary is a Mediterranean plant of origin and does best when conditions mimic that geographic area. It won't tolerate freezing temperatures. If it froze over the wnter, it will be difficult for it to recuperate. Barring that, Rosemary is also somewhat demanding as to watering habits. It doesn't like to be overwatered, i.e., standing in damp soil. It would be best to prune it severely back to any green growth showing and water about once per week thoroughly, (be sure the planter drains well through perforations in the bottom) but allow the soil to dry just as thoroughly before watering again... (it also requires lots of sunshine... 5 to 8 yours per day, if possible.) Best of luck!